Review of Nondestructive Evaluation Methods Applicable to Construction Materials and Structures

Home , Hydrostatic test, Nondestructive testing

NBS A111D2 fiDfifl3b PUBLICATIONS NAFL INST OF STANDARDS & TECH R.I.C. OF COMMERCE All 102808836 Mathey, Robert G/Revlew of nondestructlv QC100 .U5753 N0.1247 1988 V198 C.I NBS-P Itandards

NBS Technical Note 1247

Robert G. Mathey and James R. Clifton

\'BS NBS NBS NBS NBS NBS NBS NBS NBS NBS iS NBS NBS NBS NBS NBS NBS NBS NBS NBS Ni NBS NBS NBS NB:^ BS NBS NBS NBS IS NBS NBS NBS NBS NBS NBS NBS NBS NBS N \o.> ,voS NBS NBS NBS /v/>o ,%/>.> \/j.> SBS l\l}^> iS NBS NBS NBS NBS NBS NBS NBS NBS NBS N NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS iS NBS NBS NBS NBS NBS NBS NBS NBS NBS N. \BS NBS NBS NBS NBS NBS NBS NBS NBS iS NBS NBS NBS NBS NBS NBS NBS NBS NBS N '" NBS ,\/>:> viio National Bureau ofStandards .\BS " iS NBS NBS NBS NBS NBS NBS NBS NBS NBS TV I NBS NBS NBS NBS NBS NBS NBS NB' S NBS NBS NBS NBS NBS NBS NBS NBS N ^BS NBS NB HS NB S NBS NBS NBS NBS NBS NBS NBS NBS N. Tm he National Bureau of Standards' was established by an act of Congress on March 3, 1901. The Bureau's overall J^^ goal is to strengthen and advance the nation's science and technology and facilitate their effective appUcation for public benefit. To this end, the Bureau conducts research to assure international competitiveness and leadership of U.S. industry, science arid technology. NBS work involves development and transfer of measurements, standards and related science and technology, in support of continually improving U.S. productivity, product quality and reliability, innovation and underlying science and engineering. The Bureau's technical work is performed by the National Measurement Laboratory, the National Engineering Laboratory, the Institute for Computer Sciences and Technology, and the Institute for Materials Science and Engineering.

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NBS Technical Note 1247 ^f ^/

Review of Nondestructive Evaluation Methods Applicable to Construction Materials and Structures

Robert G. Mathey and James R. Clifton

Center for Building Technology National Engineering Laboratory National Bureau of Standards Gaithersburg, MD 20899

Prepared for:

Naval Civil Engineering Laboratory Port Hueneme, CA 93043-5003

June 1988

U.S. Department of Commerce C. Waiiam Verity, Secretary

National Bureau of Standards Ernest Ambler, Director National Bureau of Standards U.S. Government Printing Office For sale by the Superintendent Technical Note 1247 Washington: 1988 of Documents, Natl. Bur. Stand. (U.S.), U.S. Government Printing Office, Tech. Note 1247 Washington, DC 20402 203 pages (June 1988) CODEN: NBTNAE .

PREFACE

This is the second compilation of nondestructive evaluation (NDE) methods for construction materials and structures prepared by the Center for Building Technology. Significant advances in NDE methods for construction materials and structures have been made since the first report was published in 1982 [1]. Readers, undoubtedly, are aware of NDE methods not included in the present compilation, which should be included in a future version. The authors welcome suggestions regarding additions to the compilation of NDE methods.

An extensive effort was required in the preparation of this report and if the anticipated growth in NDE occurs then preparation of a future version, in the same format, may become unwieldy. It is recommended, therefore, that starting with the present report the compilation be coded in an expert system form. This would facilitate the identification of appropriate NDE methods for specific materials and problems. Also, additions to the compilation could be easily introduced into the expert system program, thereby, reflecting the current state-of-the-art

During the preparation of this report, it became obvious to the authors that an improved bases needs to be developed for interpreting the results of NDE inspections. At present, interpretation is frequently based on intuition and past experiences which are generally not recorded and, thus, are not of help to new inspectors. Without an adequate bases for interpretation, incorrect decisions could be made regarding the condition of building materials, components, or structures. Therefore, it is recommended that a standard practice, guide, or methodology be developed for interpreting the results of NDE tests.

iii ABSTRACT

Nondestructive evaluation (NDE) methods for evaluating in situ construction materials and for condition assessment of building components and systems were identified and are described. This report is intended to help inspectors and those involved in condition assessment choose appropriate NDE methods for specific building materials, components, and systems. Important properties of building materials along with important performance requirements for building components are listed, and appropriate NDE methods for determining these properties are recommended. In many cases the advantages and limitations of the NDE methods are presented. Potential NDE methods which may or may not require further research and development before they are ready for routine use were also identified and are briefly described. In addition, ASTM standards for NDE methods for concrete and other building materials and components were identified.

In a related aspect of the study, current Navy practices relative to the use of NDE methods in the construction and service cycle of buildings and other structures were reviewed. This review was based on Navy reports and documents provided by NCEL and NAVFAC, and on discussions with NAVFAC personnel involved with buildings and structures problems where NDE methods are used for diagnostic purposes. Navy Guide Specifications were examined for required tests, both NDE and destructive, of in situ building materials and components.

Key Words: Building components; building diagnostics; building materials; condition assessment; construction materials; in situ evaluation; nondestructive evaluation.

iv . 31

TABLE OF CONTENTS

Page

Abstract Iv

1 . INTRODUCTION 1

1 . Background 1 1.2 Objective 2

1 . Scope 2

2 . REV lEW OF CURRENT NDE NAVY PRACT ICES 4

2.1 Guide Specifications 4 2.2 Summary of NDE Practices Obtained from Brief Discussions with NAVFAC Personnel 4 2.3 Review of Needed and Presently Used Methods Based on the Results of Responses to NCEL Questionnaires 5

2.3.1 List of Reported Needed NDE Methods 6 2.3.2 List of Reported Presently Used NDE Methods 7

2 .4 Navy NDE Publications 8

3 NDE METHODS 11

4. NDE TABLES 13

4.1 Building Materials, Components, and Systems 13 4.2 Survey of NDE Methods 14

5. DESCRIPTION OF NDE METHODS 37

5.1 Acoustic Emission Method 37 5.2 Acoustic Impact Method 39 5.3 Air Flow 41

5.3.1 Pltot Traverse 41

5.4 Air Infiltration Measurements 42

5.4.1 Tracer-Gas Decay Method 42 5.4.2 Fan Pressurlzatlon Technique 43 5.4.3 Acoustic Method 44 5.4.4 Smoke Tracer 45

5.5 Air Permeability 46 5.6 Break-Off Method 46 5.7 Cast-ln-Place Pullout 47 TABLE OF CONTENTS (Continued)

Page

5.8 Electrical Potential Measurements 49 5.9 Electromagnetic Methods 51

5.9.1 Eddy Current Inspection 51 5.9.2 Magneto- Inductive Methods (Magnetic Field Testing) ... 54 5.9.3 Cover Meters 55 5.9.4 Magnetic Particle Inspection 57 5.9.5 Steel Fiber Content 60

5.10 Holography 60 5.11 Leak Testing Method 61 5.12 Longitudinal Stress Waves 62 5.13 Maturity Concept 63 5.14 Microwave Inspection 65 5.15 Middle Ordinate Method 66 5.16 Moisture Detection Methods 67

5.16.1 Electrical Resistance Probe 67 5.16.2 Capacitance Instruments 69 5.16.3 Nuclear Meter 70 5.16.4 Infrared Thermography 72

5.17 Nuclear Density Meter 72 5.18 Paint Inspection Gages 73

5.18.1 Tooke Gage 73 5.18.2 Pencil Test 73 5.18.3 Magnetic Thickness Gages 74

5.18.3.1 Magnetic Pull-Off Gage 74 5.18.3.2 Magnetic Flux Gage 74

5.18.4 Wet Film Thickness 75

5.18.4.1 Interchemical Wet Film Thickness Gage 75 5.18.4.2 Pfung Gage 76 5.18.4.3 Notch Gage 76

5.19 Pin Hole Detector 77

5 . 20 Point-Load Test 78 5.21 Probe Penetration Method 79 5.22 Proof Load Testing 82 5.23 Pull-Off Test 82 5.24 Radar 84 5.25 Radioactive Methods 85

vi TABLE OF CONTENTS (Continued) Page

5.25.1 Radiography 86 5.25.2 X-ray Radiography 86 5.25.3 Gamma Radiography 87 5.25.4 X-ray Fluorescence Analyzer 90

5.26 Seismic Testing 91

5 .27 Soil Exploration 92

5.27.1 Cone Penetration Test 92 5.27.2 Helical Probes 92 5.27.3 Standard Penetration Test 93

5.28 Surface Hardness Testing 94

5.28.1 Static Indentation Tests 94 5.28.2 Rebound Hammer Method 96

5.29 Thermal Inspection Methods 99

5.29.1 Infrared Thermography 101 5.29.2 Envelope Thermal Testing Unit 104 5.29.3 Heat Flow Meter 105 5.29.4 Portable Calorimeter 106 5.29.5 Spot Radiometer 107

5 .30 Ultrasonic Pulse Methods 109

5.30.1 Ultrasonic Pulse Velocity 110 5.30.2 Ultrasonic Pulse Echo 113

5.31 Uplift Resistance 115

5.32 Visual Inspection 116

5.32.1 Optical Magnification 116 5.32.2 Fiberscope 117 5.32.3 Liquid Penetrant Inspection 118

5.33 Water Permeability of Masonry Walls 120

5.34 Combinations of Nondestructive Evaluation Methods 121

6. SUMMARY 124

7. ACKNOWLEDGMENTS 125

8. REFERENCES 126

vii TABLE OF CONTENTS (Continued)

Page

APPENDIX A. REVIEW OF NAVY GUIDE SPECIFICATIONS A-1

APPENDIX B. REVIEWED NAVY GUIDE SPECIFICATIONS THAT CONTAIN REQUIRED NDE TESTS B-1

APPENDIX C. LISTS OF REVIEWED NCEL TECHDATA SHEETS AND NCEL TECHNICAL AND RESEARCH REPORTS THAT CONTAIN NDE METHODS C-1

APPENDIX D. ASTM STANDARDS FOR NDE METHODS FOR CONSTRUCTION MATERIALS AND BUILDING COMPONENTS D-I

vlil tiST OF TABLES

Page

Table 1. NDE Methods for Inspecting Hardened Concrete 15

Table 2. NDE Methods for Inspecting Masonry and Masonry Materials ... 16

Table 3. NDE Methods for Inspecting Wood and Lumber 16

Table 4. NDE Method for Inspecting Metals 17

Table 5. NDE Methods for Inspecting Roofing Systems 18

Table 6. NDE Methods for Inspecting Paints and Coatings 19

Table 7. NDE Methods for Inspecting Soils 20

Table 8 . NDE Methods for Inspecting Sealants 20

Table 9, NDE Methods for Inspecting Thermal Insulation 21

Table 10. NDE Methods for Inspecting the Building Envelope 22

Table 11. NDE Methods for Inspecting Pipe and Drainage Systems 23

Table 12. NDE Methods for Inspecting, Heating, Ventilation, and Air Conditioning Systems 23

Table 13. Operation, Principles, and Applications of Commonly Used and Potential NDE Methods for Inspection of Building Materials and Systems 24

Table 14 . Gamma Ray Sources 88

Table 15. Pulse Velocities in Concrete Ill

Table A. Review of Navy Guide Specifications A-2

Table B. Reviewed Navy Guide Specifications that Contain Required NDE Tests B-2

Table CI. List of Reviewed NCEL Techdata Sheets that Contain NDE Methods C-2

Table C2. List of Reviewed NCEL Technical and Research Reports that

Contain NDE Methods * C-3

Table Dl . ASTM Standards for NDE Methods for Concrete D-2

Table D2. ASTM Standards for NDE Methods for Construction Materials and Building Components D-3

~^ ix

1. INTRODUCTION

1 . 1 Background

Nondestructive evaluation (NDE) methods offer significant advantages over traditional laboratory and field methods for determining the properties of construction materials, especially in the making of in situ measurements of these materials. There are many NDE methods and they may be used in all phases of the construction and service cycle of buildings and other structures, beginning with the construction phase and continuing through the maintenance, repair, and rehabilitation phases. Currently used NDE methods and other methods based on emerging and advanced technology may be used in the maintenance, repair, and condition assessment of buildings and facilities. In addition, NDE methods may serve as an Important tool in building diagnostics to assist in assessment of their condition because of construction deficiences and changes in occupancy or mission or materials properties.

The National Bureau of Standards (NBS) completed a study in 1982 for the

U.S. Army Construction Engineering Research Laboratory (CERL) entitled,

" In-Place Nondestructive Evaluation Methods for Quality Assurance of Building

Materials" [1]^. Since then, advances in the state-of-the-art of some NDE methods have taken place. The Naval Civil Engineering Laboratory (NCEL) and the Naval Facilities Engineering Command (NAVFAC) asked NBS to review current

Navy NDE practices and to update the 1982 study [1]. This report is a revision of the earlier study and includes additions to the tables of NDE methods and to the text which describes the NDE methods. The list of ASTM standards for

•• Figures in brackets indicate references listed in Section 8.

1 isuti. methods applicable to building materials is revised and updated. Based on reports and documents provided by NCEL and NAVFAC, a review of current Navy

NDE practices is presented along with a brief summary of NDE studies.

1.2 Objective

The objectives of this study are: (1) to update the 1982 NBS study,

" In-Place Nondestructive Evaluation Methods for Quality Assurance of Building

Materials" [1] by identifying new NDE methods which can be used for condition assessment and to help to assure the quality and uniformity of in-place construction materials; and (2) to review current Navy practices relative to the use of NDE methods in the construction and service cycle of buildings and other structures.

1.3 Scope

Since completion of the 1982 NBS study [1], there have been advances in the state-of-the-art of some NDE methods. These advances in NDE methods for construction materials and condition assessment of buildings and structures have been included in this report. The information presented in this report was obtained from the literature and from those knowledgeable in the field.

The 1982 NBS study [1] was the source for a considerable portion of the information. No laboratory research was performed during the course of this study. Discussions were held with members of technical committees which cover the selection and use of NDE methods and with researchers who have evaluated some NDE methods. ASTM standards were reviewed to identify those applicable for NDE methods which may be used for the in situ evaluation of construction materials and condition assessment of building components and structures. Emerging NDE methods that have application to the diagnostic needs of the Navy were identified. These are considered to be methods which recently have been demonstrated to be sufficiently reliable to either be used in the field without further development or which need minimal further development.

Promising advanced NDE methods which require further research and development before they are ready for routine use were also identified. Needed research in the area of NDE methods for construction applications of the Navy was addressed.

Current Navy practices relative to the use of NDE methods in the construction and condition assessment of buildings and other structures were reviewed. Information for this review was obtained from Navy reports and documents provided by NAVFAC and NCEL. The review of Navy practices regarding

NDE methods included information from reports dealing with their use, evaluation, and research.

Over 200 Navy Guide Specifications were examined for required tests, both

NDE and destructive, of in situ building materials and components. A list of the required NDE tests included in the Navy Guide Specifications was compiled. 2. REVIEW OF CURRENT NDE NAVY PRACTICES

2.1 Guide Specifications

NAVFAC provided NBS with 239 Guide Specifications for review with regard

to NDE in situ tests (field tests) of building materials and components. The

list of Guide Specifications and the corresponding required field tests, both

NDE and destructive, are given in Appendix A. NDE tests were required in 29

of the reviewed Navy Guide Specifications. A list of these 29 Guide

Specifications along with the in situ NDE tests are presented in Appendix B.

2.2 Summary of NDE Practices Obtained from Brief Discussions with NAVFAC Personnel

Discussions with NAVFAC personnel indicated that the Engineering and

Design staff are involved with limited and special problems with buildings and

structures where NDE methods are used. As an example, with regard to condition

assessment of concrete, cover meters are used to determine rebar location and

thickness of concrete cover. The penetration probe and rebound hammer are

also used to assess concrete properties. Load tests of buildings and structures

are conducted. In these tests American Concrete Institute (ACI) recommendations

are followed for concrete structures. Strain gages and deflection gages are

used for making measurements. It was reported that NCEL has equipment to detect

vibrations in buildings that have been subjected to earthquakes and contain

cracks in order to assist in the assessment of the condition of these buildings.

In addition, NCEL has instrumented new buildings in order to obtain base line

data of the properties of these buildings.

Leak detectors are used to detect leaks in pipe lines, including joints.

Methods used have included ultrasonics and detection of gas. Welds are inspected by different methods including liquid penetrant inspection. It is desirable to determine the condition of underground pipe lines and to predict their service life. Included in the condition of underground pipes is the number of leaks (water, gas, steam, etc.) and the size and wall thickness of the pipes. It was reported that the Naval Research Laboratory (NRL) has developed methods for determining delamination of honeycomb panels using ultrasonic and acoustic emission techniques. It was also reported that NCEL has a device for determining locations where corrosion is occuring in precast and prestressed concrete piles. Underwater piles are difficult to inspect. The

Navy's Chesapeake Division is involved in the evaluation of underwater structures.

NAVFAC has a program aimed at development of condition assessment

Standards for buildings, structures and utilities, such as PAVER (pavements) and ROOFER (roofs) in order to provide consistency in inspections. It is difficult to make usable technology available for condition assessment of these facilities. Pavement inspections are mostly visual but ultrasonic and radar techniques are used. These NDE methods are generally applicable at specific locations. Skid resistance measurements are made on runways,

2,3 Review of NDE Needed and Presently Used Methods Based on the Results of Responses to NCEL Questionnaires

In the fall of 1985 the NCEL sent questionnaires to Navy Public Works

Centers regarding their needs and practices to assess nondestructively the quality of new construction and the condition of existing shore facilities.

Eight of the responses that were received from Navy Public Works Centers were

reviewed and a brief summary of the reported needs for Inspections and assessment of the quality of new construction and the condition of existing

facilities are presented along with presently used NDE methods. 2.3.1 List of Reported Needed NDE Methods

• early Identification of problems with water front structures

• under-pler construction, methods for condition assessment and maintaining existing systems

• underwater inspection of wharves, piers, and underwater structures (currently divers must visually Inspect pilings and sheet piles)

• underwater TV camera for Inspection of piling underneath piers

• assessment of condition of underground heat distribution systems

• leak location detector for heating distribution systems

• extent of corrosion in piping, pumps and reservoirs

• location of underground piping

• detection of underground piping leaks

• remote monitoring of systems performance and condition of components of facilities

• condition of underground utility systems including leak detection (steam, electrical, natural gas, water, fuel)

• portable metering of utilities performance as a diagnostic tool in utilities management and maintenance

• moisture detection device for inspection of built-up roofs

• condition of cast iron piping and earthen dams

• inspection of underground storm drain and sewer lines

• methods for determining condition of underground storage tanks and for leak detection

• device to check for faults in power line insulation

• device to identify faults in pipe walls

• means for checking energy efficiency of building insulation (possible solution Is the use of an infrared camera)

• infrared scanner to Inspect insulated heating pipe

• early detection of minor trouble with large pieces of dynamic equipment pavement analysis equipment for early defect detection

detection of worn or thin Insulation on steam, chill water, and other pipelines

determination of condition of transformers

development of an exterior painting condition assessment computer program

monitor condition of major transformers

condition assessment for wood buildings including termite damage of wood components

training program in diagnostics and condition assessment technology

3.2 List of Reported Presently Used NDE Methods

location of underground piping leaks (methods used include Injection of helium and SF5 into compressed air systems to pinpoint leaks)

leak location detector for heating distribution systems

infrared scanning of polelines , switchgear, electrical equipment, electrical panels, and steam traps to Identify anomalous sources of heat

infrared scanning of building exteriors to identify heat leakage

nuclear meter for detection of moisture in roof surveys

electrical resistance probe for detecting moisture in walls, roofs, and slabs of buildings

ultrasonic testing to determine the wall thickness of condensate pipe lines and their condition while the line is still in service

ultrasonic testing to measure the wall thickness of metal pipes and l:hickness of fuel storage tank siding and floor

examination of sewer lines with a TV camera to determine their condition (visual inspection with remote monitor)

transformer condition can be judged from an analysis of its insulating fluid

extent of wood decay and deterioration by puncturing with an ice pick and tapping with a hammer

extent of termite damage using an audio scope. ,:

2.4 Navy NDE Publications

Some Navy publications dealing with the inspection of buildings, design criteria, research, and relevant NDE methods which were provided by NCEL and NAVFAC were reviewed with regard to current Navy practices, evaluation methods, and recent research. The manual, "Inspection of Shore Facilities,"

Volume 2, NAVFAC MO-322 , May 1978, provides maintenance inspection/service checklists for buildings, grounds, utility plants, utility and distribution systems, and components of Navy shore facilities. It provides a guide for developing and implementing an effective and efficient preventive inspection system. Only visual inspections are listed in this manual. Another Navy manual "Engineering and Design Criteria for Navy Facilities", NAVFAC F-34

August 1985, lists specifications and standards relative to Navy facilities which are issued by government agencies (public sector) and private sector organizations. This design manual refers to nondestructive evaluation of butt welds in crane and railroad rails.

Some NCEL Techdata Sheets containing information about NDE inspections or the use of NDE equipment which were provided by NCEL were reviewed. Techdata

Sheets usually give a brief explanation of an NDE method or a brief description of NDE equipment and its use. In many cases the Techdata Sheets are based on a technical or research report which gives background data, research results, and details pertinent to the NDE methods or equipment. A list of the NCEL

Techdata Sheets that were reviewed is given in Appendix C. The following examples are given regarding NDE methods contained in the Techdata Sheets • Inspection of painting • Measuring water permeability of masonry walls • Leak detection in pipelines • Infrared thermometers for roofing inspections • Use of penetration probe test system for strength evaluation of concrete in Naval construction • Problems with underwater ultrasonic inspection • Inspection methods for wood fender and bearing piles • Locating and tracing buried metallic pipeline

Many different NDE methods are included in the Techdata Sheets. Most of the NDE methods are listed in the tables in Section 4 of this report and described in Section 5.

Some NCEL technical and research reports provided by NCEL and NAVFAC were reviewed with regard to NDE methods and equipment. These reviewed reports are also listed in Appendix C. They contain information about many types of NDE methods and in many cases research results, assessments of NDE methods, comparisons of NDE methods, the significance of the methods, their accuracy and reliability, and their use in the field are presented. Examples of the information regarding NDE methods in the technical and research reports include

the following:

• Pulse echo ultrasonic testing has been investigated for measuring the corroded metal thickness of steel piles. Results of ultrasonic evaluations have been compared to resistance probing and coring for condition assessment of wooden waterftont structures.

• Information is available about instructions for inspection and testing of railroad and ground level trackage. NDE methods used are ultrasonic inspection, optical instrument surveying, electromechanical relative displacement measurements, inertial displacement measuring transducer, proximity sensors, and laser-based level devices.

• Assessment of cables and wire rope is carried out using alternating current to produce an electromagnetic field to detect loss of metallic areas in the wire rope. For smaller wire rope, a portable NDE device that employs an audible signal detected by a head set can indicate flaws.

• Moisture can be detected in roofing systems based on surveys using nuclear moisture meters, infrared thermography, and capacitance meters. .

With regard to underground utility lines, an NCEL state-of-the-art survey found no existing techniques capable of nondestructive condition assessment. Utility companies and water distribution agencies use sonic detectors for leak detection. It was reported that none of the six techniques investigated, acoustic emission,

radiography, sonic , ultrasonic , eddy current, and magnetic flux, were suitable for Navy use on buried pipelines. Ground penetrating radar was investigated as a method for detecting underground utility lines

Extensive internal damage can be detected in underwater timber piles by an impact hammer sounding technique. The pile is struck with a hammer and damage is assessed from the acoustic response.

Small portable infrared specti'ophotometers that were introduced commercially for field analysis of gases and liquids were modified in order that organic solid materials could be identified and analyzed, This modified portable instrument showed promise that organic construction materials (paints, plastics, insulations, etc.) could be identified in the field. This could help provide for proper maintenance. It also could help ensure that specified materials were used by the contractor, and deterioration of protective coatings could be detected.

10 3. NDE METHODS

The NDE methods are listed in Tables 1 through 13 in Section 4 and descriptions of the NDE methods are given in Section 5. The tables and descriptions of the NDE methods have been updated from the previously mentioned 1982 NBS study [1]. A considerable portion of the information in the present report was taken from the previous study. It is noted that some in situ NDE tests may or may not cause minor damage to materials or buildings components. An example of an instrument that may cause minor damage is an electrical resistance probe to determine the moisture content of insulation.

The NDE tables in Section A list key properties of commonly used building materials and NDE methods for estimating the level of these properties or characterizing the materials. Operation, principles, and applications of the

NDE methods are outlined in Table 13, These tables are intended to familiarize

those personnel involved with quality assurance and condition assessment of building materials and components with NDE methods, and to help in the selection of appropriate methods. More detailed information about the NDE methods or descriptions of the methods are provided in Section 5. Appendix D lists

standard test procedures which the American Society for Testing and Materials

(ASTM) has issued for some NDE methods covered in this report.

To use the information in this report most effectively, begin with

Tables 1 through 12. If, for example, the quality and uniformity of in-place

concrete seem questionable, further inspection could be justified. The options

for inspection of hardened concrete are given in Table 1. Concrete properties

are given in the first column and appropriate NDE methods for each property

are found in the second column. For the example given, four methods are listed

11 for determining the general quality and uniformity of hardened concrete:

(1) penetration probe, (2) rebound hammer, (3) ultrasonic pulse velocity, and

(4) radiography (gamma). The methods are not ranked; the table simply provides a list of applicable methods. To help decide which of these methods would be appropriate for a specific application (considering factors such as equipment availability, cost, and information obtained), consult Table 13. For more information before selecting any of the four methods, refer to Section 5 which gives detailed information about the NDE methods.

The cross reference features of the tables can be used in the same way for information about other recommended NDE methods.

Note that the information in this report is not intended to supersede existing guide specifications. In cases of conflict, the guide specifications are to be followed.

12 4. NDE TABLES

4.1 Building Materials, Components, and Systems

Major building materials, their important properties, and NDE methods for estimating the value of these properties or for characterizing the materials are given in Tables 1 through 9. Materials considered are:

Table No. Building Material

1 Concrete 2 Masonry materials 3 Wood and lumber 4 Metals 5 Roofing 6 Paints and coatings 7 Soils 8 Sealants 9 Thermal insulation

The following building components and systems are covered in Tables 10 through

12:

Table No. Components and Systems

10 Building envelope 11 Pipe and drainage systems 12 Heating, ventilation, and air conditioning systems

In Tables 10-12, the main performance requirements are listed, and NDE methods intended for determining if these requirements are being met are

also listed.

The selection of the building materials, components, and systems addressed

in this report was largely based on considerations of: (1) the amount of

their use; (2) the frequency and severity of problems caused by deficiencies

in their quality, uniformity, or performance; and (3) the value of using NDE

methods to inspect the material, component, or system. As an obvious example,

NDE inspection is not necessary to determine that a glass window is broken,

13 while locating reinforcing steel in concrete is more readily done by NDE inspection than by coring. Researchers from the NBS Center for Building

Technology and from the NBS Office of Nondestructive Evaluation of the National

Bureau of Standards, and personnel of the U.S. Army Corps of Engineers collaborated in the selection process in the earlier NBS study [1],

In Tables 1 through 12, the column headed "Currently Recommended NDE

Methods" lists ways of testing various material properties. These tests are commonly used, and their limitations are well known. The column headed

"Potential NDE Methods" lists NDE methods that may prove useful, but are still being assessed. In some cases, suitable NDE methods are not available, as an example, for the inspection of the bond between a sealant and its substrate (Table 8).

4.2 Survey of NDE Methods

The operation, principles, and applications of recommended NDE methods for inspecting building materials are outlined in Table 13. Self-explanatory

NDE methods such as the use of rulers and visual inspection methods are not included in Tables 1 through 12.

Once construction inspectors and those involved in condition assessment become familiar with the advantages of using NDE, they may wish either to train people in their own organizations, or to obtain help from persons knowledgeable about NDE inspections. Comments on the expertise the user needs, equipment costs, and safety requirements are intended to help potential users decide which path to follow.

14 Table 1

NDE Methods for Inspecting Hardened Concrete

Currently Reconmended NDE Methods Potential NDE Methods

Location Location Property Method in Report ^ in Report ^ Method

Strength Penetration Probe 5.21 5.30. Ultrasonic pulse velocity Rebound Hammer 5.28. 5.20 Point-load test Cast-ln-place pullout 5.7 5.23 Pull-off test Maturity concept 5.13 5.6 Break-off method

General quality Penetration Probe 5.21 5.30.2 Ultrasonic pulse echo and uniformity Rebound Hammer 5.26.2 5.1A Microwaves Ultrasonic pulse velocity 5.30.1 5.24 Radar Radiography 5.25.1 5.5 Air permeability

Thickness 5.1A Microwaves (radar) 5.25.3 Gamma radiography 5.30 Ultrasonic pulse, velocity and echo 5.9.1 Eddy current 5.25.1 Radiography

Air content 5.17 Neutron density gage

Stiffness Ultrasonic pulse velocity 5.30.1

Surface texture Visual 5.32 5.14 Microwaves

Density Radiography 5.25.3 5.17 Neutron density gage Ultrasonic pulse velocity 5.30.1

Rebar depth Cover meter 5.9.3 5.14 Microwaves (radar) and position Radiography 5.25.3 5.30. Ultrasonic pulse echo 5.24 Radar

Corrosion state Visual 5.32 of reinforcing Electrical potential 5.8 steel measurement

Presence of Acoustic impact 5.2 5.29.1 Infrared thermography subsurface voids Ultrasonic pulse echo 5.30.2 5.24 Radar or delamlnatlons Radiography 5.25.3 Ultrasonic pulse velocity 5.30.1

Moisture content 5.14 Microwaves and moisture 5.16.3 Nuclear penetration

Cement content 5.16.3 Nuclear

Durability Visual 5.32

Steel fiber 5.9.5 Electromagnetic method content

Critical and 5.1 Acoustic emission rupture loads 5.30.1 Ultrasonic pulse velocity (crackabillty factor)

^ Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

15 Table 2

NDE Methods for Inspecclog Masonry and Masonry Materials

Qirrently Reco—ended NDE Methods Potential NDE Methods

Location Location NDE Property Mathod Id Report * In Report * Hethod

Integrity of 4cou«tic lapact 5.2 5.30.2 Ultrasonic pulie echo masonry Radiography J.25.3 5.14 Microwaves Probe holes with 5.32.2 5.24 Radar fiberscope Dltraaonlc pulse velocity 5.30.1

Thickness of Probe holes 5.32 5.9.1 Eddy current asonry 5.30.2 Ultrasonic pulse echo 5.25.1 Radiography

Reinforcing steel Cover aeter 5.9.3 5.30.1 Ultrasonic pulse echo (location and Radiography 5.25.3 5.14 Microwaves size) 5.25.1 Radiography

Presence of Probe holes 5.32 5.30.2 Ultrasonic pulse echo inner grout Radiography 5.25.3 Acoustic iapact 5.2 Ultrasonic pulse velocity 5.30.1

Moisture content Moisture aeter- 5.16.1 5.14 Microwaves and moisture electrical resistance 5.16.3 Moisture aeter- penetrstion nuclear

Presence of Acoustic iapact 5.2 5.30.2 Ultrasonic pulse echo delaninations Radiography 5.25.3 5.29.1 Theraal inspection Ultrasonic pulse velocity 5.30.1 (theraography) 5.25.2 Radiography

Water 5.33 Water peraeability perneablllty of coated masonry

* Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

Table 3

NDE Methods for Inspecting Wood and Lumber

Currently Reconaended NDE Methods Potential NDE Methods

Location Location Property Method in Report * in Report * Method

Integrity and Visual grading by 5.1 Acoustic emission general quality certified grader* 5.30 Ultrasonic pulse velocity (including grade, Proof loading 5.22 and echo aechanlcal 5.25.1 Radiography properties, and Penetration hammer assessment of 5.15 Middle ordinate method insect, mechanical 5.12 Longitudinal stress waves and decay damage*

Density Ultasonlc pulse velocity 5.30.1 Penetration hammer 5.25.1 Radiography 5.12 Nuclear density aeter

Moisture content Electric resistance 5.16.1 5.16.3 Nuclear aoisture aeter probe Surface hygrometers Capacitance Instrument 5.16.2 Microwaves absorption meter

Adhesive bond 5.2 Acoustic aethods for laminated 5.29.1 Theraal inspection wood (theraography) 5.25.1 Radiography

Dimensions Rulers, calipers, electronic measuring devices**

• Numbers in this column refere to NDE Method Nos. described in Section 5 and listed in Table 13.

• Perform on luaber before use; this method not described in Table 13. ** Because of their simplicity, methods not described in Table 13. 16 Table A

NDE Methods for Inspecting Metals

Currently Recommended NDE Methods Potential NDE Methods

Location Location Property Method In Report " In Report ' Method

A. Structural Metals

Presence and Radiography 5.25.3 5.30.2 Ultrasonic pulse echo location In Magnetic devices other materials Cover meter 5.9.3 Eddy current devices 5.9.1 Probe holes with 5.32.2 fiberscope

Type of metal Magnetic devices Chemical spot testing* Spark testing* Color* X-ray fluorescence 5.25.4 analyzer Electromagnetic methods 5.9

Cracks, flaws Radiography 5.25.3 5.10 Holography Ultrasonic pulse echo 5.30.2 5.14 Microwave Magnetic particle 5.9.4 5.29.1 Thermal inspection Liquid penetrant 5.32.3 Eddy current 5.9.1

Corrosion Electrical potential 5.8 5.9.1 Eddy current condition measurement 5.30.2 Ultrasonic pulse echo

Loose bolts Visual 5.32 5.2 Acoustic Impact rivets and screws

B. Weld Defects

Cracks Ultrasonic pulse echo 5.30.2 Radiography 5.25.3 Magnetic particle 5.9.4 Liquid penetrant 5.32.3

Lack of fusion Ultrasonic pulse echo 5.30.2 5.9.4 Magnetic particle Radiography 5.25.3

Slag inclusion Radiography 5.25.3 5.30.2 Ultrasonic pulse echo Magnetic particle 5.9.4

Porosity Radiography 5.25.3 5.32.3 Liquid penetrant 5.30.2 Ultrasonic pulse echo

Incomplete Radiography 5.25.3 penetration Ultrasonic pulse echo 5.30.2

C. Pipes and Tanks

Type of metal See Structural Metals, above

Wall thickness Eddy current 5.9.1 Ultrasonic pulse echo 5.30.2

Leaks and Leak testing 5.11 continuity

Corrosion Electrical potential 5.8 5.9.1 Eddy current condition measurements 5.30.2 Ultrasonic pulse echo

a Numbers In this Column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

* For more Information on these methods see Reference [2).

17 Table 5

NDE Methods for Inspecting Roofing Systems

Currently Recommended NDE Methods Potential NDE Methods

Location Location Property Method in Report ^ in Report^ Method

Composition Cores* — laboratory analysis, specific gravity, solvent, odor, and chemical tests to distinguish between asphalt and coal tar pitch

Moisture content Thermal inspection 5 16 .It 5.14 Microwaves of insulation (thermography) Nuclear moisture 5 16 3 meter Capacitance 5 16 ,2

Electrical resistance 5 16 1 probe

Permeability of Flood or pond water on roofing system roof followed by using methods to measure moisture content of Insulation

Seam integrity 5,29.1 Infrared thermography (single-ply) 5.30.2 Ultrasonic pulse echo

Slope and drains Flood or pond water on roof

Self supporting Proof loading 5.22 under design loads Wind uplift test (can 5.31 be destructive)

Uplift resistance Negative pressure 5.31

a Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

Destructive method

18 : .

Table 6

NDE Methods for Inspecting Paints and Coatings

Currently Recommended NDE Methods Potential NDE Methods

Location Location Property Method In Report^ In Report " Method

Number and Tooke Gage 5.18.1 type of layers

Dry film thickness

Metal 1 Magnetic pull-off gage 5.18.3.1 2. Magnetic flux gage 5.18.3.2 3. Eddy current 5.9.1 4. Tooke Gage 5.18.1

Wood: Tooke Gage 5.18.1

Wet film thickness 1. Interchemlcal gage 5.18.4.1 2. Pfund gage 5.18.4.2 3. Notch gage 5.18.4.3

Hardness Pencil test 5.18.2

Integrity (Pin holes)

Metal: Pin hole (holiday) 5.19 detector

Wood: Field microscope 5.32.1

Bond to Adhesion tester subsurface Scratch adhesion test 5.29.1 Thermal inspection (thermography)

Surface 5.18.1 Tooke gage preparation 5.32.1 Field microscope

General quality Photography — comparison color, reflectance, with standard blistering, etc. Measurement of reflectivity 5.29.1 Thermal inspection (thermography)

8 Numbers in this column refer to NDE Method Nos. described In Section 5 and listed in Table 13.

19 Table 7

NDE Methods for Incpectlng Soils

Currently Recoanended NDE Methdos Potential WDE Methods

Location Location Property Method In Report* In Report •_ Method

Adequate drainage Visual check of grade and topography*

Adequacy of 5.14 Microwave to detect backfill cavities In backfill

Density and Seismic testing (wave 5.26 5.27.2 Helical probes compaction propagation) Nuclear density meter 5.17

Moisture contents Nuclear moisture meter 5.16.3 5.16.1 Electrical resistance probe S.16.4 btfrared thermography

Stiffness 5.26 Seismic testing (wave propagation)

Permeability 5.16.4 Infrared thermography

Strength Standard penetration test 5.27.3 5.27.2 Helical probes Cone penetration test 5.27.1

Detect cavities 5.14 Microwave 5.26 Seismic testing (wave propagation) 5.29.1 bifrared thermography

° Numbers in this column refer to NDE Method Nos. described In Section 5 and listed In Table 13.

* Because of its simplicity, method not described in Table 13.

Table 8

NDE Methods for Inspecting Sealants

Currently Recoanended NDE Methods Potential NDE Methods

Location Location Property Method In Report* In Report* Method

Water permeability Electrical resistance 5.16.1 (infiltration) meter Capacitance Instrument 5.16.2

General quality and Move water Jet up the workmanship building wall (from bottom to top) and observe water infiltration — use methods given for testing for water 5.16.1 permeability 5.16.2

Bond to substrate*

B Numbers in this column refer to NDE Methods Nos. described In Section 5 and listed In Table 13.

* Destructive laboratory tests are available.

20 Table 9

NDE Methods for Inspecting Thermal Insulation

Currently Recommended NDE Methods Potential NDE Methods

Property Method In Report * in Report " Method

Performance Thermal Inspection 5.29.1 5.29.5 Spot radiometer (Infrared thermography) 5.29,3 Beat flow meter 5.29.4 Portable calorimeter 5.29.2 Envelope thermal testing unit

Location Thermal Inspection 5.29.1 5.29.5 Spot radiometer (Infrared thermography) 5.29.3 Heat flow meter Fiberscope 5.32.2

Moisture contents 5.16.2 Capacitance instrument 5.16.1 Electrical resistance meter 5.29 Thermal inspection

Corroslveness Measure electrical potential 5.8 of metals In contact with insulation

B Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

21 A

Table 10

NDE Methods for Inspecting the Building Envelope

Cjrrently Recommended NDE Methods Potential NDE Methods

Component Main Performance Location Location or System Requirements Method in Report" in Report" Method

Walls and No penetration 5.16.2 Capacitance Ceilings by rain water instrumentation 5.32.2 Fiber scope 5.16.3 Nuclear meter 5.16.1 Resistance probe

Retard heat Thermal 5.29 5.29.1 Thermal inspection transmission Inspection (thermography) 5.29.5 Spot radiometer 5.29.3 Heat flow meter 5.29.4 Portable calorimeter 5.29.2 Envelope thermal testing unit

Building envelope Air Infiltration 5. 5.4.1 Tracer gas tightness measurement 5.4.4 Smoke tracer

Infrared thermography 5.29.1 5.4.3 Acoustic method

Foundation Supports building and Basement Prevents Visual crack settlement survey Level readings — change with elapsed time* Strain gage buttons on cracks* Photographic recording of cracks with elapsed time*

Prevents upward Moslture meter 5.16 movement of moisture

Prevents Visual and/or 5.32 basement slab level readings - movement change with elapsed time*

Roof No penetration Nuclear moisture 5.16.3 5.16.2 Capacitance instrument by rain water meter Thermal inspection 5.16.4 (thermography)

Self-supporting Proof loading 5.22 under design loads

Retard heat Thermal inspection 5.16.4 transmitting (thermography)

Floor Levelness Level readings — change with elapsed time* Carpenter's level* Supports design Proof loading 5.22 service loads Joining details 5.25.3 Radiography and construction 5.32.2 Fiberscope practices and materials

" Numbers in this column refer to NDE Methods Nos. described in Section 5 and listed in Table 13.

* Self-explanatory; not described in Table 13.

12 Table 11

NDE Methods for Inspecting Pipe and Drainage Systems

Currently Reconmiended NDE Methods Potential NDE Methods

Performance Location Location Requirements Method In Report ^ In Report ^ Method

Does not leak Leak testing 5.11

Proper flow rate Measure volume of Flow meter water flowing during connected time Interval* to outlet

Proper flow Hydrostatic pressure pressure gage

Dielectric joints Measurement of 5.32.2 Inspection by between dissimilar electrical resistance fiberscope metals across joint*

Prevention of back Direct measurement Determination flow of gases of water in trap* of pressure of proper component

^ Numbers in this column refer to NDE Methods Nob. described in Section 5 and listed in Table 13.

* Self-explanatory; not described in Table 13.

Table 12

NDE Methods for Inspecting Heating, Ventilation, and Air Conditioning Systems

Currently Recommended NDE Methods Potential NDE Methods

Performance Location Location Requirements Method in Report ^ in Report ^ Method

Proper air Air flow 5.4.1 flow level measurement (ventilation) (tracer gas) 5.3.1 Pltot traverse

Air ducts Leak 5.4.3 Sound Amplification properly sealed detection* 5.32.2 Fiberscope 5.4.4 Smoke tracer

8 Numbers in this column refer to NDE Methods Nos. described in Section 5 and listed in Table 13.

* Self-explanatory; not described in Table 13.

23 1

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OJ OJ B ft. ft JJ o 3 rH O O E iH 1 UH kl 18 tj o to JJ !^ t8 JJ > CO .— u-l tv) •o to e kl kl p. 03 to • .r^ W • iH OJ E to 01 XI Q iH O -H 18 OJ £ m o r o m tl. •^ u-l r-J Ou •-< m 3 Qu to m O kl Z JJ 3 S 36 5. DESCRIPTION OF NDE METHODS
The descriptions of the NDE methods generally include information about the methods, descriptions of the methods, applications of the methods, and the advantages and limitations in using the methods. In some cases, other information about the NDE methods is presented such as reliability of a method and calibration of NDE equipment. In other cases, however, because information was not available in the literature some information such as advantages and limitations of the NDE methods may not be included in this section of the report.
~~5.1 Acoustic Emission Method~~
In this method, stress waves originating within the test object are detected by surface transducers [2]. The acoustic waves result from the sudden release of stored strain energy when either pre-existing or newly created flaws propagate under the action of an applied stress field. The types of flaw propagation that can be detected include dislocation movement in metals and microcrack growth in metals or brittle solids such as concrete.
Thus, acoustic emission can indicate the start of mechanical failure — i.e., yielding or fracture. The test object must undergo stress so that flaws will appear or propagate; static flaws are not detected by acoustic emission.
~~Description of Method~~
Acoustic emission testing is a passive technique; only an acoustic wave detection instrument is required. The acoustic waves, which may have a frequency range from audible to ultrasonic, are detected by piezoelectric transducers attached to the surface of the test object. The existence of
~~37 flaw growth can be detected by a transducer anywhere on the test object~~
(provided that there is enough wave amplitude to be detected). Thus, the location of transducers relative to pre-existing flaws is not critical in this method unless it is required to locate the flaw. The transducers generally detect waves in the frequency range of 50 kHz to 10 MHz [2], Detected signals are amplified; the amount of necessary amplification depends on the source of the acoustic emission. Signals from dislocation movement require greater amplification than signals from microcrack propagation. After amplification, the acoustic emission activity is processed and displayed.
~~The most useful displays are the rate of acoustic emission events (detected~~
~~signals), or the cumulative number of events plotted as a function of a pertinent parameter, such as time, applied load, or number of load cycles.~~
~~Growth of microcacks as small as 10~^ in. (2.5 x 10~^ mm) can be detected, while the minimum static flaw detectable by ultrasonic or radiographic methods~~
~~is about 0.001 in. (0.025 mm).~~
~~Applications~~
~~The method has been used to monitor the in-service behavior of pressure vessels (including nuclear reactors), to detect the onset of rapid crack~~
~~propagation under~~ ~~fatigue loading or caused by stress corrosion, and to monitor the response of systems to proof-load tests. Because acoustic~~
~~emissions give forewarning of ultimate failure, the technique can be used to~~
~~signal when loads should be reduced to prevent total failure. By using both multiple pickup of acoustic signals with transducers at different locations~~
~~and electronic data processing, regions of high acoustic emission activity~~
~~can be pinpointed, and a critical "weak link" in the system located,~~
~~38 Advantages~~
The most significant advantage of the acoustic emission method is that it gives the response of the total structure or system (in "as-built" condition) to applied loads. By observing the acoustic emission activity as loads are applied, one can find the extent of internal material degradation (yielding or fracture) as a function of load. Generally, the stage of incipient failure can be determined because this is usually accompanied by a rise in the acoustic emission rate and a rapid increase in the cumulative number of emissions.
~~Limitations~~
A major difficulty in interpreting acoustic emission results is the separation of signals caused by the loading system or by microscopic slippage at joints in the test object from the signals produced by flaw propagation in the material. Users of the technique must be aware of all the possible extraneous acoustic signals that may be detected by the transducers, and must be careful not to confuse them with signals due to flaw growth. Some background noise may be eliminated by using low frequency filters, but elimination of other noise may require more complicated methods. A high level of skill is required to properly plan an acoustic emission inspection program. Equipment costs vary from moderate ($10,000) to very expensive, depending on whether a single- or multiple-pickup system is required for the particular application,
~~5.2 Acoustic Impact Method~~
~~Description of Method~~
~~Acoustic impact is the oldest and simplest form of acoustic inspection.~~
~~In this method, audible stress waves are set up in a test object by mechanical~~
39 impact; the frequency and damping characteristics of the vibrations can be used to infer the integrity of the test object [3], In its most unsophisticated form, the test object is struck with a hammer, and the operator listens to the "ringing" caused by the resonant vibration of the object. In a more sophisticated form, a transducer is attached to the test object, and an amplifier and display unit are used to produce a visual display of the frequency and damping characteristics of the "ringing." By comparing the output with a standard representing acceptable quality, a decision is made regarding the integrity of the object.
~~Applications~~
This method can be used to detect hollow zones and delaminations in concrete and masonry structures, or it may be used to find studs behind wall-board. It also has been used to detect delaminations in laminar and composite materials.
~~Advantages~~
~~The equipment required to carry out the test is relatively inexpensive, and the test can be done easily.~~
~~Limitations~~
~~Because the "ringing" can be affected by the mass and geometry of the test object, an experienced operator may be needed to correctly interpret the results.~~
~~40 5.3 Air Flow~~
~~5.3.1 Pltot Traverse~~
~~Principle and Applications~~
Air velocity at a point in an air duct can be determined by a simple method using a pitot tube in conjunction with a suitable manometer. The velocity in a duct is seldom uniform across any section, thus a traverse is usually made to determine average velocity since a pitot tube reading indicates velocity at only one location. In general, air velocity is greatest near the center and lowest near the edges or corners. The ASHRAE Handbook indicates that in round ducts, at least 20 readings should be taken along two diameters of equal areas. In rectangular ducts, take readings in the center of equal areas across the cross section of the duct. The number of spaces should be at least 16, and need not exceed 64 [4]. To determine average velocity in the duct from the readings obtained, average the calculated individual velocities or the square roots of the velocity heads.
~~If there is a disturbance in the air flow in the duct, the pitot tube should be located at least 7.5 diameters downstream from the disturbance.~~
The type of manometer used with a pitot tube depends upon the velocity pressure being measured and the desired accuracy. A draft gage of appropriate range is usually satisfactory for velocities greater than 1500 fpm. For low air velocities, a precision manometer is essential. There are many forms of pitot tubes that have been used to make air velocity measurements.
~~41 5.4 Air Infiltration Measurements~~
~~Principle and Applications~~
~~Air leakage is the uncontrolled entry of outdoor air into a building.~~
Air leakage tests are performed to determine the tightness of buildings and to determine whether overall building ventilation is adequate. With regard to building tightness, air leakage tests provide data to determine primarily the natural air leakage rates occurring in the building under various climatic conditions and use patterns, tightness of the building compared with other buildings and with itself after corrective measures have been completed, location of leakage paths in the building, and the magnitude of each leakage path.
Measurements of both building air leakage and air exchange rate can be made using tracer gases. The rate of decay of concentrations of these gases which are introduced in the air in buildings is the technique used. Another way to measure building envelope tightness is the fan pressurization technique.
~~5.4.1 Tracer-Gas Decay Method~~
The tracer-gas decay method is very versatile and is reported to be the simplest of the tracer-gas measurement systems [5]. It can be used for both short and long term measurements. The air measuring equipment may be located on site or the air samples may be collected into air bags and analyzed off site. Injection of the tracer gas and measurements of the concentrations can be made manually or automatically to study the dependence of air exchange rates as weather changes over time.
~~A single injection of tracer gas is sufficient for each measurement and complicated apparatus is not required to control the concentration or~~
42 automatically inject gas, although several automated techniques have been developed. As much time as necessary may be allowed for mixing of the tracer gas with the air. A fan may be used initially to mix thoroughly the tracer gas with the air, or the fan may be run throughout the entire measurement procedure. It is convenient to inject tracer gas into the air handling system for the building. In this case, air is sampled at the return air ducts. If the building is large or divided into many rooms and does not have a mechanical air handling system, it may be difficult to obtain a uniform concentration of tracer gas throughout the building. It is possible that even if a uniform distribution of tracer gas exists initially, concentrations may decay at different rates at different locations in the building. The measurements will reveal the extent of the nonuniformities such as differences in ventilation rates and localized air leakage.
~~5,4.2 Fan Pressurization Technique~~
~~A building may be pressurized by a fan and the air flow rate measured to~~
~~estimate building envelope tightness. At a fixed pressure difference, the~~
~~lower the air flow rate, the tighter the envelope. In order to obtain measureable air flow rates, large pressure differences are usually introduced~~
~~in order to overcome any natural pressure differences. For even medium size~~
~~buildings this may require the use of a very large fan or simultaneous use~~
~~of a number of fans. Measurement of isolated wall and roof areas may avoid~~
~~the necessity for using large fans. This stepwise method also provides infor-~~
~~mation about permeability of individual building envelope components.~~
~~Buildings can be compared directly by expressing the induced air leakage at~~
~~a standardized pressure difference, usually 50 Pa [5].~~
43 The fan pressurization method has the advantage of simplicity, direct comparability with other buildings and times of measurement, intrinsic meaningfulness without reference to temperature and wind conditions, usefulness in locating leakage openings when used in conjunction with infrared thermography, and the ability to assess the effectiveness of retrofit measures applied one at a time.
~~5.4.3 Acoustic Method~~
~~Principle and Applications~~
This method is based on the principle that sound and air readily pass through openings in buildings. The method is simple, low cost, and can be used with minimum of training. Small openings through building structures serve as paths for both air infiltration and sound. Even very small openings in walls can significantly increase acoustic transmission compared to the case where the openings are sealed. A sound source is placed on one side of a wall and probing is carried out on the other side seeking local increases in sound levels. Almost any sound source of sufficient loudness can be used; however, preferred sources are steady and broad-band noise containing many frequencies and a saw-tooth warble tone that sweeps in frequency from
50 to 8000 Hz about three times per second. The broad band sound could be produced by a vacuum cleaner. Both sounds could be produced using a cassette tape and portable tape recorder. The warble tone works better because it is easily discernable. If the sound source is placed outside the building, the steady and broad-band sound is preferred because it is less annoying.
~~Sound can be detected near the surface and over a small area using a mechanic's stethoscope, airline plastic headset, Type I and Type II sound~~
~~44 level meters, and low-cost sound meters consisting of a battery-powered microphone and headphones.~~
~~Limitations~~
~~Lightweight walls (barriers) will only reduce sound levels slightly making it difficult to detect leaks from normal sound transmission. Insula-~~
~~tion in walls may greatly reduce the sound transmission, especially through an~~
~~air passage that is not straight through, thus making it difficult to detect~~
~~the leak. Noisy environments can also cause problems in the application of~~
~~this method.~~
~~5.4.4 Smoke Tracer~~
~~Ptinciple and Applications~~
~~Some of the commercial smoke tracer systems include guns, pencils, and~~
~~sticks. These systems provide a controlled smoke source so that at leakage~~
~~sites a thin stream of smoke may be observed. Pressurizing the interior and~~
~~thereby causing the smoke to flow outward through any openings is the preferred method. The controlled smoke source should be located close to the suspected~~
~~leakage site.~~
~~Limitations~~
~~Knowledge of suspected leakage sites is necessary in order to limit leak~~
~~detection efforts. This will enable the controlled smoke source to be located~~
~~near the leak site. The smoke must be used sparingly because of annoyance~~
~~to building occupants and possible material damage. This is a locally used~~
~~technique and therefore no extensive use of smoke is recommended in the~~
~~building interior,~~
~~45 5.5 Air Permeability~~
~~Research results suggest that the measurement of the air permeability of~~
~~concrete is effective in forecasting the carbonation rate and compressive~~
~~strength of site concrete.~~
~~Description of Method~~
~~This test method provides an estimate of air permeability of concrete in~~
~~situ. The test method involves boring a small diameter hole about 2 in.~~
~~(50 mm) in depth in the concrete. The hole is plugged and sealed at the~~
~~surface of the concrete. A hypodermic needle is pushed through the plug and~~
~~a vacuum pressure is applied to the needle. The time for the pressure to~~
~~increase to a predetermined level is taken as a measure of permeability.~~
~~Research has concluded that the air permeability test is an effective tool~~
~~for evaluating the durability and carbonation rate of aged concrete and for~~
~~forecasting the compressive strength of site concrete [6].~~
~~Limitations~~
~~The feasibility of using the air permeability methods for inspecting~~
~~concrete has not been demonstrated. Further development work is required if~~
~~the air permeability method is to become a reliable NDE method to evaluate~~
~~the quality of concrete.~~
~~5.6 Break- Off Method~~
~~The break-off test is used to determine concrete strength at the site.~~
~~Description of Method~~
~~A circular slit about 2 in. (50 mm) in diameter and 3 in. (75 mm) in~~
~~depth is formed in the concrete either by placing plastic cylinder forms in~~
46 fresh concrete and removing them after curing, or by drilling into hardened concrete [7,8]. A transverse force is applied, using a hydraulic testing device, to the top portion of the concrete cylinder to fracture the resulting core in the concrete. Fracture or break-off of the core generally occurs along the embedded end (depth) of the circular slit in the concrete due to the transverse force. The measured transverse force can be correlated with the compressive strength by using calibration charts.
~~Advantages~~
This in situ test has proven to be a suitable method for in-situ monitoring the quality of concrete. It has been accepted world-wide and has been approved as a test method in a number of national codes and standards including those in Norway and Sweden [7]. The test is a simple, economical, and practical means to determine concrete strength at the site. Further tests can be conducted immediately if the results suggest this to be necessary.
~~Limitations~~
~~The concrete needs to be repaired at locations where the cores were broken off from the concrete.~~
~~5.7 Cast-in-Place Pullout~~
The pullout test measures the force required to pull out a steel insert, with an enlarged end, which has been cast in the concrete. A pull-out device may also be inserted into a hole drilled in hardened concrete. The concrete is subjected to complex stresses by the pullout force, and a cone of concrete is removed at failure. The pullout forces are usually related to the compressive strength of the concrete, with the ratio of pullout
47 strength (force divided by surface area of the conic frustum) to compressive strength being in the range of 0.1 to 0.3. Correlation graphs are used to relate pullout force to compressive strength. There are several commercially available test apparatuses for measuring the pullout resistance of concrete.
~~Description of Method~~
ASTM has issued a standard test method, C 900, which describes in detail the pullout assembly and gives allowable dimensions [9]. The pullout insert is cast in place during the placing of fresh concrete. As noted, a pull-out device may also be inserted into a hole drilled in hardened concrete. The insert is either pulled completely out of the concrete, or pulled until maximum load is reached, with a manually operated hollow tension ram exerting pressure through a steel reaction ring. Testing and calculation procedures are also given in ASTM C 900. Techniques have been developed so that the inserts can be embedded deep in concrete, thereby permitting testing of the interior concrete.
Because the pullout insert is usually cast in place during placing of the fresh concrete, these tests must be planned in advance. Alternatively, hardened concrete can be drilled to receive the pullout insert. This necessitates drilling through the bottom or backside of a concrete slab, for example, to the proper depth and width to permit the insertion of the enlarged head. A smaller hole, permitting insertion of the steel shaft, is drilled through the remaining portion of the concrete slab. The insert is placed through the bottom or backside, and the test is performed.
~~48 Reliability of Method~~
Malhotra [10] and Richards [11] have shovm that the pullout method can reliably estimate the compressive strength of concrete. Malhotra [10] found that the coefficients of variation for pullout test results were in the same range as obtained from testing standard cylinders in compression. Correlation coefficients of 0.97 to 0.99 have been obtained for normal weight concrete from curve fitting of pullout and compression test results.
~~Advantages and Disadvantages~~
The pullout technique is a nondestructive test method which directly measures a strength property of concrete in place. The measured strength is generally thought to be a combination of tensile and shear strengths. The major disadvantage of the pullout test is that a cone of concrete is sometimes pulled out, necessitating minor repairs. However, if the pullout force is quickly released just when failure begins, the concrete cone will not be torn loose, and no repairs will be required. Another disadvantage is the need to plan where inserts are to be located and to make provisions for them before placing concrete. The feasibility of drilling holes into hardened concrete and of inserting pullout devices was explored [12]. This would eliminate the need to install the inserts prior to placing concrete.
~~5.8 Electrical Potential Measurements~~
Information on the corrosion state of metals can be obtained from measuring the electrical potential difference of the metal using a standard reference electrode and a voltmeter. If the metal has a certain difference in electrical potential, active corrosion is very likely.
~~49 Measurements on Steel in Concrete~~
~~The electrical potential method is commonly used to assess the corrosion~~
~~condition of steel reinforcement in concrete. The electrical potential differences of steel reinforcement are measured by making an electrical~~
~~connection from a voltmeter to the reinforcement, and a second electrical connection from the voltmeter to a reference cell in physical contact with~~
~~the surface of the concrete. Dry concrete must be moistened before electrical measurements are made. A saturated copper-copper sulfate electrode~~
~~is commonly used as the reference cell. The electrical potential difference~~
~~of the reinforcement below the location of the reference cell is measured.~~
~~If the electrical potential difference of the steel reinforcement is more negative than -0.35 volts versus the copper sulfate electrode, active~~
~~corrosion is probably taking place. Values in the range of -0.30 to -0.35 volts seem to suggest that corrosive conditions are developing within the~~
~~concrete, while values less negative than -0.30 volts indicate that the~~
~~steel is probably passive — i.e., not corroding [13].~~
~~An electrical potential difference diagram of a concrete slab can be~~
~~constructed in which areas of similar potential differences are outlined.~~
~~This diagram can be used to identify areas where the reinforcement may be~~
~~corroding.~~
~~Advantages~~
~~The equipment is inexpensive, and only a moderate amount of skill is~~
~~needed to make the measurements. Measurements of the electrical potential~~
~~differences of steel reinforcement provide information concerning the~~
~~probability of corrosion.~~
~~50 Limitations~~
Information on either the rate or the extent of corrosion is not obtained. In addition, a direct electrical connection must be made to the reinforcing steel. If the steel is not exposed, then some concrete covering must be removed.
~~5.9 Electromagnetic Methods~~
The presence of flaws or changes in composition of metals will affect their electrical and magnetic properties. Therefore, it is possible to infer the presence of anomalies by making measurements which rely on the electrical and magnetic properties of metals. The following NDE methods can be used: eddy current testing, magneto-inductive testing, and magnetic particle testing.
~~Also, a method has been proposed for in situ measurement of steel fiber content of steel fiber reinforced concrete.~~
~~5.9.1 Eddy Current Inspection~~
Eddy current inspection is a versatile NDE method based on the principles of electromagnetic induction; it is applicable to inspection of metals [2] and to the measurement of the thickness of nonconductive coatings on a conductive metal [14].
~~Description of Method~~
A coil carrying an alternating electric current will have an associated alternating magnetic field which acts to oppose the flow of current into the coil. When the coil is brought near a conductive material, the alternating magnetic field will induce in the material a closed loop current flow known as eddy current. The eddy currents will also be alternating, and, therefore,
~~51 .~~
a secondary magnetic field is associated with them. The secondary magnetic field will oppose the magnetic field of the coil. When the energized coil is brought near a metal surface, there will be a change in the current flow in the coil. Measuring the changes in the current flow (or the coil impedance) is the basis of eddy current inspection.
~~The magnitude of the changes in the coil current will depend on the intensity of the eddy currents induced in the metal. Factors which influence the intensity of eddy current flow include:~~
1 the frequency and magnitude of the coil current 2. the electrical conductivity of the metal 3. the magnetic permeability of the metal 4. the size and shape of the test object 5. the proximity of the coil to the test object 6. the presence of discontinuities or inhomogeneities in the metal [15].
~~The electrical and magnetic properties of the metal are controlled by alloy composition, microstructure, and residual stress [2].~~
~~Eddy Current Inspection Systems~~
The principal elements of an eddy current inspection system include the inspection coil, and oscillator to provide coil excitation, a detector to monitor changes in coil impedance, and an output device to display the test results. Various coil geometries are available, depending on the specific application. An important principle when inspecting for discontinuities is that the maximum signal is obtained when the eddy current flow is transverse to the flaw. Thus, the user needs to understand the relationships between coil configuration, eddy current flow and type of flaw to be detected.
The frequency of the excitation current affects the depth of the eddy currents and the sensitivity of flaw detection. The coil frequency can be increased to detect small, near-surface flaws; penetration is reduced, but
52 sensitivity is increased. If sub-surface flaws are to be detected, a lower frequency should be used; however, the minimum size of flaws that can be detected is increased. Thus, there is a trade-off between penetrating ability and sensitivity; this is also common to other inspection methods. The range of frequencies is from 200 Hz to 6 MHz, with the lower frequencies used primarily for inspecting ferromagnetic metals [2],
The detector circuit can also take many forms, depending on the application of the instrument. In any case, the changes in coil impedance that occur during inspection are small; bridge circuitry, similar to that used to monitor electrical resistance strain gages, is used to detect these changes. In making a measurement, the impedance bridge is first balanced by using an internal adjustment or placing the coil on a reference object of acceptable quality; then the coil is placed on the test object. Any difference between test object and reference object will result in an imbalance of the bridge which is indicated on the output device. There are many output devices; audible alarms, meters, X-Y plotters, strip-chart recorders, magnetic tape, storage oscilloscopes, and computers.
~~Instrument Calibration~~
Because many factors may affect the coil impedance when a test is performed, the object used to calibrate the instrument must be carefully chosen. For example, to detect cracks, the reference object must have the same electrical and magnetic properties as the test object; otherwise, differences in alloy composition could be interpreted as a crack. Therefore, a user must be knowledgeable about operating an eddy current device in order to calibrate it properly and to interpret test results.
~~53 Applications~~
Eddy current inspection has many uses, including the detection of flaws such as cracks, porosity, or inclusions in metals; detection of changes in alloy composition or microstructure; and the measurement of the thickness of nonconductive coatings on a metal.
~~Limitations~~
One important limitation of eddy current inspection is the volume of material examined. The inspection depth depends on the penetration depth of eddy currents, the intensity of which decreases exponentially with depth.
The strength of the signal due to a particular defect will depend on the nearness of the coil to the surface of the test object. As this distance called "lift-off" increases, the signal strength diminishes. The "lift-off" effect is so strong that it may mask signal changes due to defects.
Therefore, care must be taken to ensure uniform contact between coil and test object; it may be difficult to test objects with rough or irregular surfaces. The "lift-off" effect may be used to measure the thickness of nonconductive coatings on conductive metals, or non-magnetic metal coatings on magnetic metals. Proper calibration samples are required in order to use an eddy current instrument as a thickness gage.
~~5.9.2 Magneto- Inductive Methods (Magnetic Field Testing)~~
This technique is only applicable to ferromagnetic metals and is primarily used to distinguish between steels of different alloy composition and different heat treatments. The principle involved is electromagnetic induction.
~~The equipment circuitry resembles a simple transformer in which the test object acts as the core [2], There is a primary coil connected to a power supply~~
54 delivering a low frequency (10 to 50 Hz) alternating current, and a secondary coil feeding into an amplifier circuit. In the absence of a test object, the primary coil induces a small voltage in the secondary coil, but when a ferromagnetic object is introduced, a much higher secondary voltage is induced,
The nature of the induced signal in the secondary coil is a function of the magnetization characteristics of the object. Changes in these characteristics are used to distinguish between samples of different properties. As in the case of eddy current inspection, this method can only be used for quantitative measurement if proper calibration is performed.
~~5.9.3 Cover Meters~~
Cover meters are portable, battery-operated magnetic devices that are primarily used to estimate the depth that reinforcing steel (bars and tendons) is embedded in concrete, and to locate its position. In addition, some information can be obtained regarding the dimensions of the reinforcement [10],
~~Principle and Applications~~
Cover meters are based on the magneto-inductive principle. A magnetic field is induced between the two faces of the probe (which houses a magnetic core) by an alternating current passing through a coil. If the magnetic
field passes through concrete containing reinforcement , the induced secondary current is controlled by the reinforcement. The magnitude of this change in inductance is measured by a meter. For a given probe, the magnitude of the
~~Induced current is largely controlled by the distance between the steel reinforcement and the probe.~~
~~The relationship between the induced current and the distance from probe to the reinforcement is nonlinear, largely because the magnetic flux intensity~~
~~55 of a magnetic material decreases with the square of the distance. In addition,~~
the magnetic permeability of the concrete, even though it is low, will have some effect on the reading. Therefore, the calibrated scales on the meters of commercial equipment are nonlinear. Also, a meter must be readjusted
~~if a different probe is attached.~~
~~The probe is highly directional — i.e., sharp maximum in induced current~~
~~is observed when the long axis of the probe and reinforcement are aligned, and when the probe is directly above the reinforcement.~~
~~Some commercial cover meters can measure concrete cover over reinforcement~~
~~up to 8 in, (200 mm). By using spacers of known thickness, the size of~~
~~reinforcing between 3/8 and 2 in. (10 to 50 mm) can be estimated.~~
~~Another possible application of the cover meter is to estimate the~~
~~thickness of slabs which are accessible from both sides. If a steel plate is~~
~~aligned on one side with the probe on the other side, the measured induced~~
~~current will indicate the thickness of the slab. For this application, a~~
~~series of calibration tests must be performed first, British Standard~~
~~BS 4A08 gives guidance for the use of cover meters.~~
~~Advantages~~
~~Cover meters are portable, inexpensive instruments that can be easily~~
~~used. They are useful when reinforced concrete has only one layer of~~
~~widely separated reinforcing bars.~~
~~Limitations~~
~~In highly reinforced concrete, the presence of secondary reinforcement~~
~~makes it difficult to determine satisfactorily the depth of concrete cover.~~
~~Furthermore, reinforcing bars running parallel to that being measured~~
~~56 influence the induced current if the distance between bars is less than two or three times the cover distance [10].~~
~~5.9.4 Magnetic Particle Inspection~~
~~Principle of Method~~
This inspection method relies on the tendency of cracks to alter the flow of a magnetic field within a metal so that fine magnetic powder will be attracted to the crack zone, allowing cracks to be Identified [2,16,17], For example, consider a bar magnet in which the magnetic field flows through the magnet from south to north poles. If ferromagnetic particles are sprinkled over the middle surface of a crack-free magnet, there will be no attraction because the magnetic field lies wholly within the magnet. Now consider a cracked magnet; the two sides of the crack acts as north and south poles, and the magnetic field bridges the gap. However, some of the magnetic field will leak out of the magnet into the air, and ferromagnetic powder would be attracted by the leakage field. Therefore, the attraction of the powder indicates a crack. A subsurface crack would also produce a leakage field, but the response would be weaker than for a surface crack.
~~Application of Method~~
In using the magnet particle method, it is necessary to magnetize the object being inspected, apply ferromagnetic particles, and then inspect for cracks. Two general types of magnetic fields may be induced in the test object: circular and longitudinal. A circular field is produced by passing an electric current through the test object: the magnetic field then would be concentric with the direction of current flow. A longitudinal field could be created by placing the test object inside a coil carrying electric
57 current: the magnetic field then would be parallel to the longitudinal axis of the coil. The direction of the magnetic field relative to the test object controls which cracks will be detected. Strong leakage fields are produced by cracks which intersect the magnetic lines of force at an angle; no leakage fields are produced by cracks parallel to the magnetic lines of force.
~~Therefore, complete inspection should include rotation of the test object with respect to the magnetic field to make sure that all existing cracks intersect the magnetic field lines.~~
In field inspections, it usually is not practical to pass a current through the entire part or surround the part with a coil. Portable units are available that permit inspection of small portions of the test object at a time. For example, prods can introduce a flow of current between two contact points on the object. In this case, a circular magnetic field is Induced. A yoke — a U-shaped electromagnet in which the poles are brought into contact with the test object — can also be used. With a yoke, a longitudinal magnetic field is set up in the object, and the lines of force in the electromagnet run from one pole to the other. With either portable method, only a small portion of a large test object can be inspected at one time; 12 in. (300 mm)
~~is a practical limit for spacing between prod contacts [2].~~
~~The choice of current used to magnetize the test object is important.~~
~~If subsurface cracks are to be detected, direct current should be used because alternating current will only produce a magnetic field near the surface.~~
~~The direct current may be from a constant or pulsating source, though the~~
~~pulsating type is preferred because it imparts greater mobility to the~~
~~ferromagnetic powder. The current supply is low voltage and very high amperage~~
~~for user safety, but still permits strong magnetization of the test object.~~
~~58 Inspection is usually carried out with the current on, but if the metal has high retentivity (permanent magnetism), the current may be turned off before the powder is applied.~~
The powder used to indicate the leakage fields may be dry or suspended in a liquid. Dry powders are preferred for the best sensitivity to subsurface cracks and should be used with direct current. Wet powders are superior for detecting very fine surface cracks. To improve visibility, powders are available in various colors, providing high contrast with the background. In addition, fluorescent particles are available for increased visibility.
~~Advantages~~
The magnetic particle inspection method has several advantages over other crack detection systems [2]. Portable equipment is available that can be readily taken to the inspection site. This equipment is inexpensive and simple to operate; positive crack indications are produced directly on
~~the part and no electronic equipment is needed. Any part that is accessible~~
~~can be Inspected.~~
~~Limitations~~
~~This method will only work with ferromagnetic metals. For complete~~
~~inspection, each area needs to be inspected more than once using different~~
~~magnetic field directions; very large currents are needed to inspect large~~
~~areas at once. Experience and skill are needed to interpret properly the~~
~~particle indications and to recognize patterns which do not indicate cracks.~~
~~Demagnetization may be required after inspecting steels with high magnetic~~
~~retentivity. The maximum depth of the flaw detection is about 0.5 in. (13 mm),~~
~~and the detectable flaw size increases as flaw depth increases.~~
59 Portable equipment is limited with regard to the current available for the inspection. For detection of deep lying discontinuities and for coverage of large areas with one prod contact, a larger machine, such as a mobile unit or stationary unit with higher-amperage output is required.
~~5.9.5 Steel Fiber Content~~
~~Description of Method~~
The electromagnetic apparatus for measuring steel fiber content of steel fiber reinforced concrete consists of a measuring device and several attachments having circular or square openings in the center into which the test specimens are inserted [18]. In the attachments there are coils for both excitation and induction of an electric current. With an increase in steel fiber content of the specimen in the attachment, the induced electric current increases. Based on this principle, the steel fiber content can be determined from a reading of the induced current. This method can be used for both hardened and fresh concrete. For fresh fiber reinforced concrete, it must be placed in molds that do not contribute to the induced electric current.
~~Limitations~~
~~This electromagnetic method for in situ measurement of steel fiber content in hardened and fresh concrete shows promise as a research tool.~~
~~The method has not been used extensively in the field. Further development work is required it if is to become a reliable NDE method.~~
~~5.10 Holography~~
~~Description of Method~~
~~Two methods available for nondestructive inspection are optical holography, using visible light waves, and acoustical holography, using ultrasonic waves.~~
60 In these methods, a two step process creates a three-dimensional image of a diffusely reflecting object [14], The first step involves recording both the amplitude and phase of any type of coherent wave motion emanating from the object,
~~The recording of this information in a suitable medium is called a hologram.~~
At a later time, the wave motion can be reconstructed from the hologram to regenerate a three-dimensional image having the shape of the object. The nondestructive inspection of an object is accomplished by using the regenerated three-dimensional image as a template against which any deviations in the shape or dimensions of the object can be observed and measured [14],
~~Limitations~~
Skill is required in developing holograms (three-dimensional images) and in the interpretation of comparing holograms in order to measure deviations that have occurred in the shape or dimensions of the object that is inspected.
~~5.11 Leak Testing Method~~
~~Principle of Method~~
Leakage testing is the detection and sizing of holes in pipes and tanks which permit the escape of liquids or gases [19]. There are many different methods of leak testing, but they can be generally classified into two categories. In the first, the leaking system is monitored under normal operating conditions. This includes the use of pressure meters, the application of a soap solution, or the use of audio or amplified listening devices.
In the second category, a particular substance is added into the system flow to provide special indications of leakage. This includes additives such as colored dyes, Freon 12 and helium gas, radioactive tracers, and odorous indicators.
~~61 Applications~~
Many leak detection methods are suitable for fi«ld application. Liquid storage vessels and above ground piping can usually be checked visually for leakage under normal operating conditions with no special equipment. Gas- carrying systems usually can be checked best in the field with a soap solution or (with freon gas added to the system) a propane torch. These systems have no special power requirements, and none of the equipment involved weighs more than 5 lb (2 kg).
~~Advantages~~
Leak detection methods can locate flaws too small to be found by any other NDE technique. Leaks with rates as small 10"^^ cc/sec can be detected with radioactive tracers and radiation monitoring devices, while a soapy water solution can locate leaks with rates as low as 10"^ cc/sec [19].
~~Limitations~~
~~Flaws can be detected only if they penetrate through a structure that can be held at pressure conditions exceeding those of the surrounding atmosphere.~~
~~5.12 Longitudinal Stress Waves~~
~~Description of Method~~
The speed that longitudinal (parallel to the grain) stress waves travel in wood has been measured by resonant frequency, impact, and by ultrasonic stress-wave devices [20]. Stress wave-speed (speed of sound) of waves that travel in the longitudinal direction is affected by several factors such as moisture content, temperature, knots, specific gravity, and orientation of
62 grain in the wood (grain angle). The type of longitudinal stress wave induced in wood does not have a significant effect on stress wave-speed. Stress waves show promise for rapid lumber grading and predicting mechanical properties of wood [20].
Development of an effective in situ test method to evaluate the soundness of wood subject to deterioration would be useful in appraising its service life. Wood members under some environmental exposures may lose some structural integrity through decay or chemical degradation. Stress-wave transmission has been investigated to determine nondestructively the extent and location of degradation in wood [21].
~~Limitations~~
~~Additional research is needed to demonstrate the feasibility of using longitudinal stress waves to assess the mechanical properties of wood and for rapidly determining the quality of wood members.~~
~~5.13 Maturity Concept~~
~~Principle and Application of Method~~
The maturity concept has been proposed as a method for predicting early age strength development of hardening concrete. It relates the combined effect of temperature and hydration time of concrete to its strength [22].
~~Maturity (M) is usually expressed as:~~
~~M = Z (T-To)At where T = temperature of the concrete~~
~~Tq = the highest temperature below which the strength of hardening concrete does not change~~
~~At = the increment of time for each temperature.~~
~~63 .~~
~~According to the maturity concept, the strength of a given concrete mix is a single-valued function of maturity, independent of the actual temperature history [22]~~
~~To apply this method, one first experimentally determines the strength- maturity relation of the concrete mix to be used in building the structure.~~
~~This is done by making and curing standard specimens in a laboratory, monitoring the actual concrete temperature, and testing strength at various ages.~~
~~From the temperature record, the corresponding maturity value at each test age~~
is calculated, and strength versus maturity data are generated. Various equations for the strength-maturity relation have been proposed, and can be used in analysis of the data [23~25]. During construction, the in-place
concrete temperature is recorded, from which maturity values at any age can be determined. The previously determined strength-maturity calibration curve is used to predict the strength of the in-place concrete. The maturity method is identified in ACI Committee Report 306R-78 as a viable means of predicting the in situ strength of concrete [26].
~~Maturity can be calculated using temperature records from continuous~~
~~strip-chart recorders or from digital data-loggers, which print out the~~
~~temperature at regular time intervals. As an alternative, commercial~~
~~"maturity meters" are available; these monitor the in-place temperature and~~
~~automatically compute the cumulative maturity. Such instruments cost about~~
~~$3000. Multi-channel maturity meters have been developed to allow monitoring maturity at many locations with a single instrument. In addition, single-use,~~
~~disposable meters have been produced, although their reliability has not~~
~~been tested. Finally, one may use programmable data-loggers as maturity~~
~~meters.~~
~~64 Advantages~~
~~Because In-place temperatures are measured, the maturity method accounts for one of the major factors affecting early-age strength development of concrete.~~
~~Limitations~~
Since only temperature and time are measured, another method is needed to verify that the in-place concrete has the correct mix proportions. Other- wise, the user has no way of knowing if the strength-maturity calibration curve is appropriate. Accelerated curing tests of samples taken from the concrete batch, or other in-place tests discussed in this report may be used. Because of the nonuniform temperature distribution in the structure, the temperature probes must be carefully located to avoid overestimating maturity development in the critical strength regions. In addition, there is a question about whether the equation given earlier in this Section (5.13) is the best temperature-time function for computing maturity. Carino discussed this problem and suggested alternative methods [25]. Finally, the maturity method is only applicable for strength prediction in new construction and cannot be used to estimate the strength of concrete in existing structures.
~~5.14 Microwave Inspection~~
Microwaves (or radar waves) are a form of electromagnetic radiation which have frequencies between 300 MHz and 300 GHz corresponding to wavelengths of 1 m to 1 mm. Microwaves are generated in special vacuum tubes called klystrons and transported in a curcuit by waveguides. Diodes are commonly used to detect microwaves.
~~65 Applications~~
Because of their electromagnetic nature, microwaves can be reflected, diffracted, and absorbed. These waves are absorbed by water and this has led to development of a method for determining the moisture content of concrete.
The use of microwaves to estimate the moisture contents of concrete and roofing materials has been explored [10,27,28], Similar to capacitance instruments (see Section 5,16,2), changes in the dielectric properties of materials are detected. Since moisture affects the dielectric properties of a material, changes in moisture content in the material can be detected. Boot and Watson report that the microwave technique only estimates the moisture
~~content of concrete within 12 to 30 percent of its mean value [29], The low~~
~~accuracy of micowave inspection is largely attributed to the heterogeneity of~~
~~concrete, and the internal scattering and diffraction it causes.~~
~~Limitations~~
~~The feasibility of using microwaves for inspecting installed construction materials has not been demonstrated. Further development work is required if~~
~~the microwave method is to become a reliable field NDE method.~~
~~5,15 Middle Ordinate Method~~
~~Description of Method~~
~~In this method a laboratory instrument is used that is capable of~~
~~detecting stiffness variations within boards (lumber) over lengthwise regions~~
~~of less than two feet [30], A bending moment is applied to each end of the~~
~~board under test. Stiffness calculations are based upon the assumption that~~
~~short segments of a board undergoing bending approximate arcs of circles with~~
~~varying radii. The middle ordinate instrument measures, either on a continous~~
66 basis or in discrete steps, the perpendicular distance between the midpoint of a chord and its arc. This distance or deflection is inversely related to stiffness. The instrument provides a means of assessing in the laboratory the strength-reducing potential of defects in lumber.
~~Limitations~~
This research method has not been used in the field. Additional research and field use are needed to demonstrate the feasibility of using the middle ordinate method as a reliable NDE method to inspect lumber at the job site.
~~5.16 Moisture Detection Methods~~
~~Many of the problems encountered in a building are caused by moisture.~~
Visual inspection can reveal obvious surface moisture, but even if a surface is dry, subsurface moisture can be present. Four NDE methods are often used for moisture inspection measurements. The types of instruments or methods used include electrical resistance probes, capacitance instruments, nuclear meters, and infrared thermography [27,28,31].
~~5.16.1 Electrical Resistance Probe~~
~~Principle and Applications~~
The resistance probe method involves measuring the electrical resistance of a material, which decreases as the moisture content increases. Most instruments consist of two closely spaced probes and a meter-battery assembly which are enclosed in one housing or in two attached assemblies. The probes are usually insulated except at the tips so that the region being measured lies between the tips of the probes. The probe can penetrate soft materials, such as roofing membranes, so that moisture at various distances below the
~~67 surface can be detected. Operation of a resistance probe is very simple. A voltage is impressed between the probes and the resistance measured.~~
Probe instruments have been used for moisture detection in plaster, brick, concrete, and roofing materials. Similar procedures have been used for determining the electrical resistance of soils, except a four probe system is used.
~~Calibration~~
The electrical resistance probe and other moisture measuring instruments are usually calibrated by obtaining relationships between their response and the moisture content of materials similar to those being inspected. The moisture contents of the reference specimens are gravlmetrlcally determined
~~— l,e., specimens are weighed before and after oven drying with the differences in weight considered to be their moisture contents.~~
~~Advantages~~
The simple, inexpensive Instruments, while giving only an approximation of the extent of wetness, are useful in identifying wet areas and for determining moisture migration patterns. More sophisticated instruments appear to be capable of giving semi-quantitative information if they are properly calibrated.
~~Limitations~~
~~Electrical resistance probe instruments do not determine moisture contents precisely. When used on roofing membranes the test method is considered to be destructive.~~
~~68 .~~
~~5.16.2 Capacitance Instruments~~
~~Principle and Applications~~
~~Capacitance instruments used to detect moisture are based on the principle that moisture can affect the dielectric properties of a material [31]~~
~~The dielectric constant, K, of a material is a relative measure of the ability of a material to store electrical energy and is given by:~~
~~K = C/Co where C is the capacitance of a material and Cq is the capacitance of a vacuum~~
The dielectric constants for many dry building materials are usually low; e.g., for dry roofing materials, K ranges from 1 to 5, while water has a K of approximately 80 [28]. The value of K for a moist material will theoretically increase linearly as the volume fraction of water increases.
Capacitance-radio frequency instruments have been used to measure the moisture contents of paper products, wallboard, and roofing materials. Commercial capacitance Instruments have various electrode configurations. The electrodes are attached to a constant frequency alternating current source and establish an electrical field in the material to be tested. Current flow or power loss — indicating moisture content — Is then measured. Most Instruments operate in the radio frequency region (1 to 30 MHz).
~~Advantages~~
~~Capacitance instruments are portable and measurements can be taken rapidly.~~
~~69 Limitations~~
Capacitance meters have extreme sensitivity to surface moisture; because of this it is essential that the roof surface be dry when capacitance surveys are made [32]. An investigation by Knab et al. suggests that capacitance
~~Instruments may not give reliable quantitative measurements of the moisture contents of roofing systems beyond the "threshold" moisture content [31].~~
~~5.16.3 Nuclear Meter~~
~~Principle of Method~~
Fast neutrons, emitted during the decay of radioactive isotopes, are used in making moisture content measurements [28,29]. Fast neutrons from the isotope source enter the material and are both scattered and slowed by collisions with the nuclei of the atoms composing the material. Nuclei of all materials slow down the neutrons by momentum exchange, but the speed reduction is greatest for collisions with hydrogen nuclei, which have about the same mass as the neutrons. Some of the slow or thermal neutrons are scattered so that they reach the slow neutron detector in the instrument and are counted for a specific period of time. The thermal neutrons reaching the detector are much more likely to have collided with hydrogen nuclei than with other atomic nuclei because the scattering cross-section of hydrogen is greater than for other atoms likely to be present. The detector measures primarily the backscattering of slow neutrons which have collided with hydrogen nuclei in the surface region of materials. For example, the depth of measurement is limited to 2 to 8 in. (51 to 203 mm) in soils.
~~70 Commercial Meters and Applications~~
~~Nuclear meters are used to measure both moisture content and density of soils, portland-cement concrete, asphaltic concrete, and roofing materials~~
[10,27,28]. These meters consist of a shielded radioactive isotope source, a detector or counting device, and readout equipment. In commercial meters, the isotopes used are radium 226-beryllium, and americium 241-beryllium.
~~Both americium and radium are alpha particle emitters. These particles interact with the nucleus of beryllium, resulting in the emittance of fast neutrons.~~
In addition to neutron sources, most commercial nuclear moisture meters also have gamma ray sources. The gamma rays are used to determine the density of materials. See Section 5.25 about Radioactive Methods for an explanation of the principle.
~~Advantages~~
~~Nuclear meters are portable, and moisture measurements can rapidly be made on materials.~~
~~Limitations~~
The hydrogen atoms of building materials in addition to those of water will contribute to the number of detected thermal neutrons. For example, asphalt in a roofing membrane may contribute to a reading because it contains bonded hydrogen atoms. For hydrogen-containing materials, the meter must be calibrated with samples identical to those expected during field inspection.
Also, a license must be obtained from the Nuclear Regulatory Commission to use the radioactive isotopes in the neutron source of the neutron moisture meters. Transportation of meters may be difficult because of restrictions.
~~71 5.16.4 Infrared Thermography~~
In addition to locating heat loss, infrared thermography can be used to detect moisture in building materials if heat is flowing through them. The presence of moisture will affect the heat transfer properties of materials; this permits the identification of wet areas by thermography. The principles involved in making thermography scans are discussed under Thermal Inspection
Methods (Section 5.29). The infrared thermography method is being used in making aerial scans of roofs. Large roof areas and many buildings can be scanned in a relatively short time [27,28]. Handheld infrared cameras also are being used to measure heat losses and to detect moisture in roofing systems [32,33]. Additional applications of infrared thermography are given in Section 5.29. In using thermography to detect moisture in roof systems, it is necessary to assume that temperature gradients are caused by moisture and are not associated with differences in roofing composition or thickness.
~~Because construction and thickness variations can be present, results from thermographic inspections should be interpreted carefully.~~
~~Limitations~~
~~Some destructive testing may be necessary to verify roofing composition and thickness.~~
~~5.17 Nuclear Density Meter~~
~~See Section 5.16.3.~~
~~72 5.18 Paint Inspection Gages~~
~~5.18.1 Tooke Gage~~
~~Principles and Applications~~
The Tooke Gage measures dry paint film thickness by the microscopic observation of a small v-groove cut into the paint film. In addition, the number of paint layers and their individual thicknesses can be determined.
~~The thickness of dry coating applied to any type of surface can be measured~~
~~— e.g., to wood, metal, glass, or plastic. The Tooke Gage is easily portable, with overall dimensions of 4.5 x 3.5 x 1 in. (114 x 89 x 25 mm); and it weighs~~
~~26 oz (0.7 kg). Three cutting tips are furnished; these permit measurements of film thicknesses up to 50 mil (0.13 mm).~~
~~Limitations~~
~~A disadvantage of this method is that a cut is made in the paint film which may have to be repaired, depending on the substrate and the severity of the environment.~~
~~5.18.2 Pencil Test~~
~~Principle and Applications~~
~~This rapid and inexpensive method can be used to determine film hardness of an organic coating on a substrate using pencil leads of known hardness.~~
Testing is started with the hardest pencil lead and continued down the scale of hardness to either of two end points: (1) the pencil that will not cut into or gouge the film, or (2) the pencil that will not scratch the film.
~~Advantages~~
~~The method causes only slight damage to the coating.~~
~~73 5.18.3 Magnetic Thickness Gages~~
~~5.18.3.1 Magnetic Pull- Off Gage~~
~~Principle and Applications~~
These instruments measure thickness by using a spring calibrated to determine the force required to pull a permanent magnet from a ferrous base coated with a nonmagnetic film. The instrument is placed directly on the coating surface to take a reading. The attractive force of the magnet to the substrate varies inversely with the thickness of the applied film. The spring tension required to overcome the attraction of the magnet to the substrate is shown on the instrument scale as the distance between the magnet and the substrate.
~~5.18.3.2 Magnetic Flux Gage~~
~~Principle and Applications~~
These instruments measure coating thickness by changes in the magnetic flux within the instrument probe or the instrument itself. The instrument probe must remain in direct contact with the coating at all times during measurement. The magnitude of flux changes as an inverse (nonlinear) function of the distance between the probe and the ferrous substrate. The testing apparatus is mechanically or electrically operated. The mechanically operated instruments house an integral horseshoe magnet, the contacts of which are placed directly on the coated substrate. The electrically operated gages utilize a separate instrument probe that houses the magnet and the gages must be placed directly on the coated surface. In both types, the coating thickness is shown on the instrument scale or meter.
~~74 .~~
~~The methods for nondestructive measurement of dry film thickness of nonmagnetic coatings applied to a ferrous base are described in ASTM Standard~~
~~D 1186 (Appendix D) . In addition, the method for nondestructive measurement of film thickness of pipeline coatings on steel is described in ASTM Standard~~
~~G 12 (Appendix D) .~~
~~5.18.4 Wet Film Thickness~~
~~Measurements of wet film thicknesses of organic coatings using the~~
~~Interchemical Wet Film Thickness Gage and the Pfung Gage are described in~~
~~ASTM Standard D 1212 (Appendix D) . Wet film thickness measurements using~~
~~Notch Gages are described in ASTM Standard D 4414 (Appendix D)~~
~~5.18.4,1 Interchemical Wet Film Thickness Gage~~
The gage consists of an eccentric center wheel supported by two concentric wheels so as to provide two scales that are bilaterally symmetrical. The gage is rolled on the wet film; as it rotates there is a change in clearance between the wet film and the eccentric wheel. The point at which the film first touches the eccentric center wheel is a measure of the thickness of the paint film. The gage is available in a variety of ranges and can measure wet film thickness up to 60 mils on the English scale and up to 700 yra on the metric scale.
~~Limitations~~
~~At locations where thickness measurements are made, the coating film may have to be repaired.~~
~~75 5.18.4.2 Pfung Gage~~
~~Principle and Applications~~
The gage consists of a convex lens that is mounted in a short tube that slides freely in an outer tube. The lower surface of the convex lens has a radius of curvature of 250 mm. Compression springs keep the convex surface out of contact with the wet film until pressure is applied to the top of the short tube forcing the lens down through the film to the substrate.
~~After the pressure is released, an oversized circular spot is retained on the lens. The diameter of the circular spot retained on the lens is a measure of~~
~~the wet film thickness.~~
~~Limitations~~
~~At locations where thickness measurements are made, the coating film may have to be repaired.~~
~~5.18.4.3 Notch Gage~~
~~Principle and Applications~~
Square or rectangular, and circular, notch rigid metal gages are used to measure film thicknesses ranging from 0.5 to 80 mils (13 to 2000 pm) for square or rectangular gages and from 1 to 100 mils (25 to 2500 ym) for circular gages.
These gages are used on coatings on flat substrates. Notched gage measurements are neither accurate nor sensitive, but they are useful In determining approximate wet film thickness of coatings where sizes and shapes of coated
~~objects prohibit the use of the more precise methods given in ASTM Standard~~
~~D 1212. The square or rectangular gages are pushed perpendicular into the~~
~~film and the circular gages are rolled perpendicularly across the film.~~
~~Thickness is determined from tabs and notches wetted by the film.~~
~~76 Limitations~~
~~At locations where thickness measurement are made, the coating film may have to be repaired.~~
~~5.19 Pin Hole Dectector~~
~~Principle and Applications~~
This type of device Is used to find pin holes (holidays) In nonconductlve coatings applied to metals. Pinhole and holiday detectors are of three general types; low voltage wet sponge, direct current high voltage, and alternating current electrostatic types [34]. Most low voltage commercial
Instruments consist of a probe or electrode, which makes contact with the coating through a moist sponge, and an earth lead, such as alligator clip, which Is attached to an area of bare metal. When the moist sponge passes over a pin hole, an electrical circuit Is completed and an alarm sounds.
~~Most high voltage detectors use In general a direct current power source In~~
~~the range of 500 to 1500 volts [35]. High voltage detectors basically~~
~~function on the same operating principle as the low voltage detectors except~~
~~that a sponge Is not used. The alternating current electrostatic type~~
~~detector Is used for testing conductive linings applied over steel substrates.~~
~~Limitations~~
~~There are several problems In using the detectors to Inspect for pin holes,~~
~~If a metallic object is completely coated, part of the coating must be removed~~
~~so that the earth lead can make contact with the metal. The voltage must be~~
~~carefully selected to match the coating thickness because too high a voltage~~
~~would break through a thin film even if pin holes were not present. The~~
~~77 results are qualitative since no information on the size of a pin hole is given.~~
~~5.20 Point-Load Test~~
~~This test is intended to estimate the compressive and tensile strength of concrete using small cores.~~
~~Description of Method~~
Relatively small cores of plain or fibrous concretes about 2.7 in. (68 mm) in diameter and 4 in. (100 mm) in length are tested using a point load in a diametral test [36]. Cores have to be drilled and extracted from the concrete for which strength determinations are to be made. The apparatus for the point-load test is a portable testing machine consisting of a loading system and load measuring capability. A truncated steel cone is used to apply the point load at mid-length of the core along its diameter until failure occurs. The point-load test is essentially an indirect tensile test and will give a maximum tensile stress which differs from the actual direct tensile stress because of high compressive stress under the load. The compressive strength can be related to the tensile strength through empirical formulae.
~~Advantages~~
This test is quick to carry out, is relatively inexpensive, and can be performed in the field on a simple and easily portable apparatus. A total of six point-load tests may be expected to provide a realistic estimate of concrete strength.
~~78 Limitations~~
Additional research is needed to demonstrate the reliability of using the point-load test to assess the strength of concrete and for this test to become a reliable in situ NDE method. The concrete needs to be repaired where cores are taken,
~~5.21 Probe Penetration Method~~
~~Principle of Method~~
The probe penetration method involves measuring the exposed length of a cylindrical steel probe driven into concrete by a powder charge. This method is useful for assessing the quality and uniformity of concrete in situ, and for delineating areas of poor quality or deteriorated concrete in structures.
Probe penetration results have also been used to estimate the compressive strength of concrete by using correlation graphs. The graphs are constructed by plotting the exposed lengths of probes versus experimentally measured compressive strengths. This can be done by performing penetration tests on a concrete slab and taking core samples for compression testing.
~~Probe Equipment and Its Use~~
The Windsor Probe is the most commonly selected, and possibly the only, commercially available apparatus for measuring the penetration resistance of concrete. It consists of a special driving gun which uses a 32 caliber blank with a precise quantity of powder to fire a high-strength steel probe into the concrete. A series of three measurements is made in each test area.
~~The length of a probe extending from the surface of the concrete can be measured with a simple device.~~
~~79 .~~
~~Operating procedures for the Windsor Probe are given by the manufacturer.~~
~~In addition, testing procedures are given in ASTM Standard C 803 (Appendix D)~~
~~The probe can be easily operated by concrete inspectors, and is readily portable.~~
The manfacturer supplies a set of five calibration curves, each corresponding to a specific Moh's hardness for the coarse aggregate used in the concrete. With these curves, probe measurements can be converted to compressive strength values. However, Ami observed that use of the manufacturer's calibration curves often resulted in grossly incorrect estimates of the compressive strength of concretes [37], Therefore, the
~~Windsor Probe should be calibrated by the individual user, and should be recalibrated whenever the type of aggregate or mix design is changed.~~
The Windsor Probe can be used for assessing the quality and uniformity of concrete because physical differences in a concrete will affect its resistance to penetration. A probe will penetrate deeper as the density, subsurface hardness, and strength of the concrete decrease. Areas of poor concrete can be delineated by making a series of penetration tests at regularly spaced locations.
The Windsor Probe has been used to estimate the compressive strength of concrete. However, the relationship between the depth of penetration of the probe and the compressive strength can only be obtained empirically because the penetration of the probe depends on a complex mixture of tensile, shear, frictional, and compressive forces [37]. The estimation of compressive strengths with the Windsor Probe, therefore, must be made using a correlation diagram with appropriate confidence limits.
~~80 The probe technique appears to be gaining acceptance as a practical NDE method for estimating the compressive strength of concrete. Improved~~
~~correlations between probe results and in-place strength can be obtained by~~
~~keeping the curing conditions of the test specimens close to those expected~~
~~for in-place concrete, and by making sure that the test concrete is representa-~~
~~tive of the in-place concrete. If the Windsor Probe is calibrated using concrete~~
~~specimens taken from an early construction stage, the calibration chart could~~
~~be used to estimate the strength of concrete placed during later stages~~
~~(assuming that the concrete design is the same).~~
~~Advantages~~
~~The Windsor Probe equipment is simple, durable, requires little maintenance,~~
~~and can be used by inspectors in the field with little training. The probe test~~
~~is very useful in assessing the general quality and relative strength of~~
~~concrete in different parts of a structure.~~
~~Limitations~~
~~Care must be exercised, however, because a projectile is fired; safety~~
~~glasses should be worn. (Note: The gun can only be fired when it is pushed~~
~~against the spacer plate.) The Windsor Probe primarily measures surface and~~
~~subsurface hardness; it does not yield precise measurements of the in situ~~
~~strength of concrete. However, useful estimates of the compressive strength~~
~~of concrete may be obtained if the probe is properly calibrated.~~
~~The Windsor Probe test does damage the concrete, leaving a hole of about~~
~~0.32 in. (8 mm) in diameter for the depth of the probe, and may cause minor~~
~~cracking and some surface spalling. Minor repairs of exposed surfaces will~~
~~be necessary.~~
~~81 5.22 Proof Load Testing~~
~~Principle of Method~~
Proof load testing is based on the concept that a structure capable of surviving the stresses of a severe overloading should be serviceable under normal operating conditions [19]. Proof loading requires overloading a structure in a load pattern similar to operating conditions (e.g., high pressure in a pipeline).
~~Applications~~
Proof load testing can be used with leak testing (see Section 5.11) in pressure vessels and pipelines inspection to increase the sensitivity of leak detection. This method is generally used as a last resort to determine the adequacy of a structural system.
~~Advantages~~
~~An entire structure can be tested in its "as-built" condition.~~
~~Limitations~~
~~The test may cause the premature failure or the destruction of a structure. Proof load testing requires extensive planning and preparation, and is usually expensive.~~
~~5.23 Pull-Off Test~~
~~The pull-off test is used to estimate the in situ strength of concrete.~~
~~Description of Method~~
~~The pull-off test, used as a means of predicting the compressive strength of concrete, involves bonding a circular steel probe, 2 in. (50 mm) in diameter,~~
~~82 to the surface of the concrete to be tested [38]. The concrete surface should be properly prepared and epoxy resin used to bond the probe to the concrete.~~
A tensile force is applied to the adhered probe using a portable mechanical system; the force is increased until the concrete fails in tension. From the tensile force at failure, the compressive strength of the concrete can be determined from calibration graphs based on data from a large number of pull- off tests and corresponding cylinder compressive strength tests. Since the tensile strength of the bonded area is greater than the concrete, the concrete will eventually fail in tension. The amount of overbreak is usually small so that the area of failure can be taken as being equal to that of the probe.
~~Advantages~~
The procedure is simple, inexpensive, and does not require a highly skilled operator to make the measurements. Tests can be conducted on horizontal and vertical surfaces. The stress at failure is a direct measure of the tensile strength. Inspection of the probe after test will indicate if failure occurred in the concrete, thus unsatisfactory failures can be discounted. It is not necessary to plan the location of the test areas in advance of placing the concrete; as is the case for some other partially destructive tests.
~~The internal concrete strength can be estimated by partial coring to the desired depth and conducting the test on the cored area.~~
~~Limitations~~
Although considerable testing has been done and the tests gave consistent and reliable results, a standard test such as an ASTM test has not been developed. The concrete needs to be repaired in areas where the test was conducted.
~~83 5.24 Radar~~
Radar is capable of rapid nondestructive assessment of materials such as asphalt, concrete, soil, and rock by penetrating them to varying depths to indicate material changes, separations, voids, and other discontinuities [39].
~~Radar may also be used to estimate material quality.~~
~~Description of Method~~
Radar techniques are based on the principle that electromagnetic waves are reflected by concrete and other materials. Radar wavelengths can be longer than those associated with NDE microwave inspections. Portable equipment is available commercially for application to assessment of concrete, but the method has yet to be standardized. The radar technique has been used with success in New York and New Jersey to evaluate concrete pavements and bridge decks [40]. An attractive feature of this technique is the speed, approximately 17 km/h, at which pavements can be scanned. It is noted that great planning and skill are needed to evaluate the data.
The frequencies of the electromagnetic energy selected for radar NDE inspections range from 100 to 1200 MHz depending on penetration depth and resolution desired. The resolution or ability to differentiate closely spaced objects is a function of the signal frequency and bandwidth. Very small changes over short distances require a higher frequency and wider bandwidth.
With lower frequency and narrower bandwidth, the ability to see small changes is lessened but the depth of penetration is greater. The energy travels through different materials at a specific speed for each material depending on the material's dieletric properties. As an example, at a frequency of
~~1200 MHz and in 1 nanosecond, the radar wave will travel 6 in. (152 mm) in air,~~
84 2.5 in, (64 nnn) in concrete, and 3 in, (76 mm) in asphalt. When a change in material dieletric occurs such as at an interface of air to asphalt or asphalt to concrete it is indicated by a change in wave shape.
Low frequency radar is used for macro-studies, such as soil mapping and location of material changes in the subsurface. In micro-studies, higher frequency radar is used for locations of voids or delaminations in thin sections such as roadways and bridge decks.
~~Advantages~~
~~Radar can rapidly scan pavements and bridge decks. The data can be stored and compared with perodic scans to determine changes which occur with time.~~
~~Limitations~~
Skill is required in interpretation of data to determine with a reasonable degree of confidence the condition of materials with regard to voids, cracks, and delamination. Further development work is required if the radar method is to become a reliable field NDE method.
~~5.25 Radioactive Methods~~
There are two types of radioactive NDE methods, radiography and radiometry, used to assess the properties of in situ concrete and other materials. The radiography method uses a radioactive source in order to take a graphic picture of the interior of building components. The radiometry method involves detecting the intensity of the emerging radiation which passed through a building component. Prior calibration charts can be used to determine in situ density of building components and their thickness. Internal defects and
~~85 location of Internal parts In building components can be determined using both radiography and radiometry methods. A British standard (BS 4408, Part 3,~~
~~1970) outlines testing procedures with regard to gamma radiography.~~
~~5.25.1 Radiography~~
Radiography allows the internal structure of a test object to be inspected by penetrating radiation, which may be electromagnetic (X-ray, gamma rays, etc.) or particulate (neutrons) [2,41,42]. The object is exposed to a radiation beam, and the intensity of the radiation passing through is reduced according to the object's variations in thickness, density, and absorption characteristics,
~~The quantity of radiation passing through the object is measured and used to deduce internal structure. X-rays and gamma rays have been most widely used.~~
~~5.25.2 X-ray Radiography~~
X-rays are produced by bombarding a target material with fast moving, high energy electrons. The high energy electrons collide with electrons in the target, which are promoted to higher energy levels. As the promoted electrons return to their ordinary energy levels, their excess energy results in the emission of X-rays. X-rays are generated in an evacuated chamber
(X-ray tube) in which high energy electrons are generated by applying a very high voltage between an incandescent filament (the electron source) and the target material. By varying the voltage. X-rays with different penetrating abilities can be generated. For example, for routine Inspections using exposures of several minutes duration and with medium speed film, 200 kV
~~X-rays are capable of penetrating about 1 in. (25 mm) of steel, while 400 kV~~
~~X-rays can penetrate up to 2 in. (51 mm) of steel [25], which is generally about the maximum radiation emitted with portable equipment. Recent~~
86 developments, such as linear accelerators can speed up and Increase the penetrating power of field radiographic methods [14]. In general, the penetrating ability of X-rays of a given energy level decreases as the thickness or the density of the object increases,
~~5.25.3 Gamma Radiography~~
Gamma rays are physically indistinguishable from X-rays; they differ only in the manner in which they are produced [14]. Gamma rays are the result of radioactive decay of unstable isotopes. Thus, there are some basic differences between gamma ray and X-ray radiography. Because gamma rays are produced by nuclear disintegrations, a gamma ray source will lose its intensity with time. In addition, each source produces rays of fixed penetrating ability. Isotopes of thulium, iridium, cesium, radium and cobalt have been used for radiography. Thulium has a penetrating ability of 0.5 in. (13 mm) of steel, while cobalt produces gamma rays capable of penetrating up to 9 in. (230 mm) of steel. The gamma sources usually used for inspecting concrete are given in Table 14. Note that the relative penetration abilities of the gamma rays are controlled by their energies.
~~87 Table 14~~
~~Gamma Ray Sources [41]~~
Gamma Optimum Working Radioactive Energy Half-life Thickness of Source (MeV) (tl/?) Concrete (mm) Dose Rate*
~~Iridium 192 0.296 70 days 30-200 0.55 and 0.613~~
~~Cesium 137 0.66 33 years 100-300 0.39~~
~~Cobalt 60 1.17 5.3 years 150-450 1.35 and 1.33~~
* Roentgens per hour per curie at 1 m. One curie is equal to 3.7 x 10^^ disintegrations per second.
~~Portable gamma radiography units are available for field inspections.~~
~~Using iridium-192 or cobalt-60 in these units enables short exposure times~~
~~and good image sharpness in field applications.~~
~~Principles and Applications~~
~~Gamma and X-ray radiation is attenuated (reduced) when passing through materials. The extent of attenuation depends on the density and thickness of~~
~~the material, and on the energy of gamma rays. In radiography, differences~~
~~in radiation attenuation produced by variations in the density and thickness~~
~~of a material are recorded on photographic film. For example, when reinforced~~
~~concrete is radiographically inspected, steel reinforcement attenuates the~~
~~radiation more than concrete and appears as a lighter area in the film.~~
~~Voids and cracks in the concrete appear as darker areas on the film because~~
~~the incident radiation is attenuated little.~~
~~88 In practice, penetrating rays generated by a suitable source are allowed~~
~~to pass through materials, with the emerging radiation being recorded on X-~~
~~ray film held in a light-tight cassette. Some of the applications of gamma~~
~~radiography are inspecting concrete to locate reinforcing bars, and to determine if excess microscopic porosity or macroscopic voids are present [43];~~
~~inspecting welds for cracks, voids, and slag inclusion; and inspecting masonry walls for the presence of reinforcement or grout.~~
~~Advantages~~
~~Radiography provides a method for readily characterizing the internal~~
~~features of an in-place material or building component. This method is applicable to a variety of materials.~~
~~Limitations~~
~~The most important drawback of radiography is the health hazard associated with the penetrating radiation. The relatively high cost is another limiting~~
~~factor in the use of gamma radiography. A radiographic inspection program~~
should be planned and carried out by trained individuals who are qualified to perform such inspection. All personnel involved in radiographic inspection must carry devices that monitor the radiation dosage to which they have been
~~subjected, and must be protected so that the dosage rate does not exceed~~
~~Federal limits. Gamma ray sources are Inherently hazardous because they emit~~
~~rays continuously, and high energy sources have extremely high penetrating~~
ability. As a result, gamma ray sources require large amounts of shielding material; this limits the portability of gamma radiography equipment. The use of gamma-producing isotopes is closely controlled by the Nuclear Regulatory
~~Commission; users must have a license.~~
~~89 5.25.4 X-ray Fluorescence Analyzer~~
~~Principle and Applications~~
This method is generally carried out in the laboratory but there has been some limited use in the field. The basis of the x-ray fluorescence technique lies in the relationship between the atomic number and the wavelength of the x-ray photons emitted by the sample element. Although almost any high energy particle can be used to excite characteristic radiation from a specimen in the laboratory, application of an x-ray source offers a reasonable compromise between efficiency, stability and cost. Almost all commercial laboratory x- ray spectrometers use an x-ray source. "Since primary (source) x-ray photons are used to excite secondary (specimen) radiation, the technique is referred to as x-ray fluorescence spectrometry" [44].
In the potential NDE field method, the material is irradiated with a radioactive isotope and absorbed energy is re-emitted as x-rays characteristic of elements present in the material. The method is used for determination of the elements present in a material.
~~Advantages~~
~~The potential NDE field method provides for a rapid analysis to determine elements present in installed materials. The analyzer is portable and can be used in the field and the laboratory.~~
~~Limitations~~
~~Field analysis is limited to small regions of material per test and the technique is not capable of detecting all elements. The field apparatus requires periodic calibration with reference standards.~~
~~90 5.26 Seismic Testing~~
~~Principle of Method~~
Seismic testing is the evaluation of material integrity by analysis of shock wave transmission rates and effects [19], An array of sensing devices around an explosive charge of known energy (the most common shock load input system) is used to record shock wave transmission rates. These rates can be related to material densities. Vibrational patterns induced from shock loading can be used to determine resonant frequencies in structures.
~~Applications~~
Seismic testing can measure soil densities and locate density variation boundaries. Soil density values can then be related to load bearing capacities and foundation preparation requirements. Seismic testing can also be used to check structures for possible resonant frequencies that could cause failure under operating dynamic loads.
~~Advantages~~
~~All components of some seismic test systems are portable.~~
~~Limitations~~
Seismic testing is applicable only to monitoring soil conditions and structural vibrations. Multi-channel recording systems, power cables, and many sensing devices are needed. The hazards of explosives are also involved in the testing.
~~91 5.27 Soil Exploration~~
~~5.27.1 Cone Penetration Test~~
~~Principle and Applications~~
~~The Cone Penetration test is described in ASTM Standard D 3441. It is widely used in European practice and is gaining increasing popularity in the~~
United States [45]. The test is performed by pushing a cylinder having a conical tip into the ground. The cylinder can be described as having a 1.55 in. 2 (1000 mm^) cross sectional area, a 23.25 in.^ (15,000 mm^) surface area, and the conical tip has a 60 degree apex angle. The soil resistance is measured by the resistance to the penetration of the conical tip into the ground and the frictional forces exerted on the surface of the cylinder which are measured separately. The cone penetration test has been correlated both empirically and theoretically with the bearing capacity of deep and shallow foundations, and with the shear strength, density, stiffness and compressibility of soils.
~~5.27.2 Helical Probes~~
~~Principle and Applications~~
Helical probes have been found to be a practical and economic method for exploring soils at a shallow depth [45]. Test results correlated well with traditional in situ exploration methods and the probes were also found to be applicable for compaction control. The probes can be inserted
into the soil to a depth of 6 feet (1.8 m) . The magnitude of the torque required to insert the helix into the soil is taken as a measure of soil resistance. The probes can be operated with ease by one person. A probe could also be coupled with drillrods and used at a greater soil depth.
~~92 .~~
~~The probes consist of a helical screw connected to a 5-1/2 to 6 foot~~
(1,7 - 1.8 m) long steel shaft. A hexagonal nut at the upper end of the shaft is used for applying the torque. The probe is inserted into the ground by turning it in a clockwise direction using a torquemeter. The torquemeter has a dial gage to read the torque needed to insert the probe into the soil.
Torque readings are generally taken at 6 in. (15 cm) penetration levels, however, it is possible to also continuously monitor the torque. The rate of advance of the probe during a torque reading is kept to correspond to approximately 4s for a 180 degree turn of the torquemeter. The average torque rather than the peak value is recorded. Upon completion of the in situ soils test, the probe is withdrawn by turning it in a counter clockwise direction.
~~Limitations~~
Although extensive testing indicated that the probe test results correlated well with traditional in situ exploration methods, it was recommended that research be continued [45], Additional data are needed for controlled conditions and for soils whose characteristics are well defined. There is also a need for more data for clays and for compacted fills.
~~5.27.3 Standard Penetration Test~~
~~Principle and Application~~
~~The Standard Penetration test is described in ASTM Standard D 1586. It was developed in 1927 and is the most widely used soil exploration test in~~
~~the United States and in worldwide geotechnical engineering practice [45]~~
~~The test involves dropping a 140 Ibm (63.5 kg) hammer from a height of~~
93 30 in. (0.76 m) to drive a drillrod with a standard split-tube sampler into the ground. The number of blows to achieve a 1 ft (0.30 m) penetration by the split-tube sampler, is used as a measure of soil resistance. The Standard
Penetration test has been empirically correlated with many soil characteristics, including allowable bearing capacity of foundations, in situ shear strength, density, stiffness and compressibility, and liquefaction potential during earthquakes.
~~5.28 Surface Hardness Testing~~
Surface hardness methods are generally used to indicate the strength level or quality of a material rather than to detect flaws. Hardness in these tests refers to the resistance a material offers to indentation by an object.
~~Indentation is produced under static or impact loading conditions. The most common applications are in testing metals and concrete.~~
~~5.28.1 Static Indentation Tests~~
Static indentation tests are primarily used in testing metals. They usually involve indenting the surface with an indenter of fixed geometry under specified loads [2]. The indenter has a small point and thus at the point of contact produces stresses high enough to cause the metal to yield. A permanent indentation results. The magnitude of the indentation will depend on the hardness of the metal, the applied load, and the geometry of the indenter.
Therefore, by measuring the size of the indentation under a given set of conditions, one can get an approximate measure of the hardness. For some metals such as hardened and tempered steel, the hardness value can be used to predict with resonable accuracy the tensile strength, impact resistance.
~~94 and endurance limit [2]. Portable hardness testers are available for in-place testing of metal structures.~~
~~Standard Methods~~
~~There are three widely used methods for hardness testing of metals. The~~
~~Brlnell method involves applying a constant load (500, 1500, or 3000 kg) on a~~
0.4 in. (10 mm)-diameter hardened steel ball-type indenter, and measuring the diameter of the indentation with a microscope. A hardness number is determined by substituting the values of the applied load, ball diameter, and indentation diameter into a standard formula. An example of a Brinell test result would be 400 HB; 400 is the number calculated from the standard formula, "H" stands for hardness, and "B" for Brinell. For softer metals, one would use a smaller load to cause the indentation.
The Vickers method is similar to the Brinell method, except that a square- based, pyramidal diamond indenter is used, and the applied loads are much smaller. The diagonal of the square indentation is measured, and its value and the applied load are substituted into a standard equation to calculate the Vickers hardness number (HV).
The most common method is the Rockwell hardness test, which measures the depth of additional permanent indentation that occurs as the load is increased from a small load to the test load. The test instrument measures the depth automatically, and the hardness number is read directly from a scale on the instrument. The Rockwell test can be performed much faster than the previously described methods. There are 15 Rockwell hardness scales — five different indenters and three different loads. A hardness number of 60 on the Rockwell
~~95 C scale would be designated 60 HRC. The variety of scales permits testing a wide range of metals from very soft to very hard.~~
~~Usefulness of the Hardness Number~~
~~Tables are available that permit conversion of the hardness number from one test method to the equivalent number of another test method, for example,~~
see ASTM Standard E 140 (Appendix D) . There are also tables which give the approximate tensile strengths of metals corresponding to the different hardness numbers. Care must be taken in using the strength tables because each applies to only certain types of metals.
~~5.28.2 Rebound Hammer Method~~
The rebound method is based on the rebound theories of Shore [46], He developed the Shore Scleroscope method in which the height of rebound of a steel hammer dropped on a metal test specimen is measured. The only commercially available instrument based on the rebound principle for testing concrete is the Schmidt Rebound Hammer [47],
The technique has gained wide acceptance by researchers and concrete inspectors. It is one of the most universally used nondestructive test methods for determining the in-place quality of concrete, and for deciding when forms may be removed. According to Clifton, standards have been drafted in Poland and Romania for the rebound hammer [48]. The British
~~Standards Institution has issued Building Standard 440 which covers nondestructive test methods for concrete, and includes the rebound hammer method~~
~~in part 4 of the Standard [48]. The ASTM has issued Standard C 805, which gives procedures for the use of the rebound hammer (Appendix D),~~
~~96 Description of Method~~
The Schmidt Rebound Hammer consists of a steel weight and a tension spring in a tubular frame. When the plunger of the hammer is pushed against the surface of the concrete, the steel weight is retracted against the force of the spring. When the weight is completely retracted, the spring is automatically released, the weight is driven against the plunger, and it rebounds.
~~The rebound distance is indicated by a pointer on a scale that is usually graduated from zero to 100; the rebound readings are termed R-values. The~~
~~R-values indicate the hardness of the concrete; the values increase with the hardness of the concrete.~~
Each hammer has a calibration chart, showing the relationship between coiiipressive strength of concrete and rebound readings. However, rather than placing too much confidence in the calibration chart, users should develop their own calibration for each concrete mix and each rebound hammer.
~~Applications~~
~~Numerous investigators have shown that there is some correlation between the compressive strength of concrete and the hammer rebound number [49-51].~~
There is, however, extensive disagreement about the accuracy of the strength estimates from rebound measurements [52,53]. Mitchel and Hoagland found that the coefficient of variation for estimated compressive strength, for a wide variety of specimens from the same concrete, averaged 18.8 percent [54], Ami found that the rebound hammer gave a less reliable estimate of compressive strength than the Windsor Probe [37]. Some investigators have attempted to establish correlations between the flexural strength of concrete and the hammer rebound number. Relationships similar to those for compressive strengths
~~97 were obtained, except that the statistical variations were even greater [53,55]~~
Mltchel and Hoagland attempted to correlate rebound numbers with the modulus of specimens [54], They concluded that no valid correlations could be made. Peterson and Stoll, and Klieger have developed some empirical relations
~~between the dynamic modulus of elasticity and hammer rebound [49,56].~~
~~Advantages~~
~~The Schmidt Rebound Hammer is a simple and quick method for the~~
~~nondestructive testing of concrete in place. The equipment is inexpensive,~~
~~coating less than $1000, and can be operated by field personnel with a limited~~
~~amount of instruction.~~
~~The rebound hammer, like the Windsor Probe, is very useful in assessing~~
~~the general quality of concrete and for locating areas of poor quality concrete.~~
~~A large number of measurements can be rapidly taken so that large exposed~~
~~areas of concrete can be mapped within a few hours.~~
~~Limitations~~
~~The Schmidt Rebound Hammer, however, has recognized limitations. The~~
~~rebound measurements on in situ concrete are affected by:~~
1. Smoothness of the concrete surface 2. Moisture content of concrete 3. Type of coarse aggregate 4. Size, shape, and rigidity of specimen, e.g., a thick wall or beam 5. Carbonation of the concrete surface [10,53,57].
~~The rebound method is a rather imprecise test and does not provide a~~
~~reliable prediction of the strength of concrete.~~
~~98 5,29 Thermal Inspection Methods~~
Thermal inspection includes methods in which heat-sensing devices or substances are used to detect irregular temperatures. Thermal inspection of objects can be used to detect flaws and to detect undesirable distribution of heat during service [14], There are several methods for carrying out thermal inspections and many types of temperature measuring devices and substances. The two main types of thermal inspection are thermography and thermometry. Thermography involves mapping of isotherms, or contours of equal temperature, over a test surface; while thermometry is the measurement of temperature. Both of these methods can be conducted by means of contact and noncontact inspections. The most commonly used materials or substances for contact thermographic inspections are heat-sensitive paints, heat-sensitive papers, thermal phosphors, and liquid crystals. Infrared detectors are used for noncontact thermographic inspections. There are several basic thermal detectors used for contact thermometric inspection and they include bolometers, thermistors, thermocouples, and thermopiles. Surface temperature can be measured by noncontact thermometric inspections using radiometers and pyrometers or infrared thermometers.
The presence of discontinuities in an object, such as cracks, voids, or inclusions, will change the heat transfer characteristics of the object. Thus, if there is a transient heat flow condition, there will be nonuniform surface temperatures. The pattern of the surface temperatures can be used as an indirect indicator of subsurface anomalies [2]. Thermal inspection can also detect anomalous operating characteristics of a system, such as overloaded electrical wiring or heat loss through walls and roofs of buildings. The following discussion addresses primarily the application of thermal inspection
~~99 to detect anomalies in the internal structure of test objects such as structural metallic components and roofing systems.~~
~~Principle of Thermal Inspection~~
To establish the condition for thermal inspections, a temperature gradient must exist or be created in the test object. If necessary, this can be done by applying a temporary heat source to the front or back surface of the test object. The flow of heat from the warm to the cold surface will be affected by the material's thermal diffusivity, which is a function of the material's thermal conductivity, density, and specific heat. If there are discontinuities which have thermal dif fusivities different from that of the bulk, material, local "hot" or "cold" spots will exist on the surfaces directly over the location of the voids. Therefore, by measuring the pattern of surface temperatures under heat flow conditions, subsurface flaws can be detected.
As stated above, surface temperatures can be determined by contact or noncontact inspection methods. With contact methods, the surface is covered with a temperature-sensitive material, and differences in surface temperature are recorded as a pattern on the coating material. Examples of coatings developed for this application are: heat sensitive paints and papers; phosphor coatings for which the fluorescence, under ultraviolet light, is affected by temperature; melting point coatings which melt when a specific temperature is reached; and liquid crystals which change color as their temperatures vary.
~~Contact methods are generally not very sensitive, have relatively long response times, and require an application procedure before thermal inspection.~~
~~Noncontact methods permit remote sensing of the thermal patterns, and are the more popular thermal inspection methods.~~
~~100 .~~
~~5.29.1 Infrared Thermography~~
~~Principle of Method~~
An object having a'^temperature above absolute zero will radiate electromagnetic waves. The wavelengths of the radiation fall within certain bands, depending on the temperature. For example, at room temperature, the wavelengths are typically from 4 to 40 micrometers, with a peak wavelength of about 10 micrometers [2]. At very high temperatures, the wavelengths of the emitted radiation are reduced to less than 1 micrometer and fall within the visible spectrum, which explains why some metals give off a red color when heated to high temperatures. The longer wavelength radiation associated with room temperature is not visible to the eye. This is infrared radiation. By using instruments that can detect infrared radiation, differences in surface temperatures can be "seen." This is the basis of the thermal inspection method known as infrared thermography.
~~The rate of radiant energy emission per unit area of surface (W) is given by the Stef an-Boltzmann Law:~~
~~W=eaT^ where: T = the absolute temperature e = the emissivity a = the Stefan-Bolt zmann constant (5.67 x lO"!^ watt/cm2/°K^)~~
~~Thus, changes in the temperature of a surface produce more than proportional~~
~~changes in emitted energy, and this allows the testing equipment to detect~~
~~temperature differences as small as 0.2°C. Emissivity refers to the efficiency~~
~~of energy radiation by the surface. The maximum radiation efficiency occurs~~
~~in a "black body," and this is given an emissivity value of 1. All real~~
~~surfaces have an emissivity less than 1; polished metallic surfaces have low~~
~~emissivity, while roughly textured nonmetals have high emissivity. Since~~
101 detection methods are based on the intensity of emitted radiation, a change in emissivity at various points on the surface may be incorrectly interpreted as a change in temperature. Surfaces with nonuniform or low emissivity can be painted with high emissivity coatings.
~~Remote Inspection~~
~~Infrared thermography permits remote inspection of the test object.~~
This is possible because air is practically transparent to the infrared wavelengths associated with conditions near room temperature [28]. However, high water content will reduce the transmission of infrared radiation through air, so problems may arise when the weather is humid. Semiconductor crystals are most often used to detect infrared radiation. Their electrical properties are altered by incident infrared radiation. For best sensitivity, the crystals should be kept cold with liquid nitrogen. This places some limitations on the portability of the detection systems. Dewar flasks are needed to hold the liquid nitrogen, and the nitrogen needs to be replaced as it evaporates.
~~Infrared Scanners and Display~~
Operating on a scanning principle similar to television, infrared scanners allow the user to view a picture of the test object's surface. Through a system of special mirrors, the surface is scanned, a small spot at a time; the intensity of radiation is measured by the detector and is displayed on a cathode ray tube. The horizontal and vertical scans occur so quickly that a picture (thermogram) of the surface is reconstructed on the cathode ray tube. The picture is presented as shades of gray corresponding to variations in surface temperatures of the viewed object. A calibration strip is also
~~102 shown so that the shades can be converted to absolute temperatures if desired.~~
~~It is also possible to have a color display showing different temperatures in different colors.~~
~~Applications~~
Thermal inspection methods have been applied for detecting disbonds in laminated materials, entrapped moisture, material density gradients, and anomalies in castings [2]. In the construction area, infrared thermography has been applied to compare thermal resistances of roofs, to detect water penetration into built-up roofs, to detect heat loss through walls and roofs of buildings, and to detect overloaded electrical circuits [28]. Infrared thermography has also been used to detect deteriorated regions in bridge decks [58].
~~Advantages~~
~~Thermal inspection equipment is generally portable, and a permanent record~~
~~(photograph) can be made of the inspection results. By using infrared~~
~~thermography, inspections can be performed without direct contact with the~~
~~surface, and large areas can be rapidly inspected.~~
~~Limitations~~
~~In determing the size and location of detectable flaws, it should be~~
~~recognized that under heat flow conditions the surface temperature patterns~~
~~will be a function of the type and size of the discontinuity, its distance~~
~~from the surface, the heat intensity applied or flowing to the surface of~~
~~the object, and the observation time [2]. The sensitivity of infrared~~
~~thermography in detecting internal flaws is a complex function of these~~
~~103 variables. Therefore, the results of such inspections should be carefully~~
~~interpreted.~~
~~5.29.2 Envelope Thermal Testing Unit~~
~~Principle and Applications~~
~~The envelope thermal testing unit consists of two blankets which are~~
~~attached to opposite sides of walls and through which the heat flux to opposite~~
~~wall surfaces can be controlled [5]. This testing unit was developed by the~~
~~Lawrence Berkeley Laboratory in order to evaluate the in situ transient~~
~~thermal performance of walls. It was designed to overcome some of the~~
~~difficulties in using heat flow meters and calorimeters for the in situ~~
~~evaluation of building components. The difference between the envelope~~
~~thermal testing unit and these techniques is that the heat flow is controlled~~
~~and not the temperature.~~
~~The slightly flexible blankets made to conform to slight irregularties~~
~~in wall surfaces are placed in direct thermal contact with the wall, thus~~
~~eliminating complications associated with air film and considerably reducing~~
~~the bulk of the unit. Each blanket consists of two large area electric~~
~~heaters separated by a low-thermal-mass insulating layer. An array of~~
~~temperature sensors is embedded in each heat layer. The electric heaters are~~
~~designed to provide heat output that is uniform over the entire area and the~~
~~heat output is controlled by adjusting the voltage applied to the heaters.~~
~~In calculating the thermal resistance of a wall, the data are analyzed in~~
~~the manner as the data obtained from heat flow meters and calorimeters.~~
~~104 Limitations~~
The envelope thermal testing unit has been used only for research purposes and is considered as being under development. Only qualified technicians experienced with this procedure and also having an understanding of the fundamentals of building heat transfer should carry out this procedure.
~~5.29.3 Heat Flow Meter~~
~~Principle and Applications~~
A heat flow meter consists of a thin flat wafer, either circular or rectangular in shape, that is comprised of a series of pairs of thermocouple junctions [59]. The wafer contains an embedded thermopile which produces a voltage (millivolt) signal that is proportional to the rate of heat flow passing through the wafer. The sensitivity of a heat flow meter (millivolts per Btu/h ft^) is a function of its average temperature. "In selecting a heat flow meter for a particular application, it is Important that the heat flow meter provide a signal sufficiently large for measurement and resolution by the readout device at the lowest expected heat flow rate [5].
The thermal resistance of a building component can be measured by using a heat flow meter spot-glued to a representative location on the interior surface of the component, and temperature-sensing probes attached to the inside and outside surfaces at the same location. After the heat flow meter is bonded to the surface, it should be covered with the same or similar coating used on other parts of the surface, so that the radiative exchange between the monitored location and other surfaces in the room will be comparable. The measured thermal resistance of the component is determined by dividing the average difference in surface temperature, for a sufficient
105 period of time, by the average heat flow measured during the same time interval. For accurately calibrated heat flow meters, this technique has been shown to be accurate to within 6 percent [5], The thermal resistance measurement is applicable only to the particular spot where the heat flow meter is attached to the building component. However, when used with a
~~thermographic survey this technique becomes an effective tool for assessing the thermal performance of building components.~~
~~Limitations~~
This technique can only be used during periods when there is no reversal in direction of heat flow. Only qualified technicians should carry out this procedure. They should be experienced with techniques for making proper low- level electrical measurements and also have an understanding of the fundamentals of building heat transfer. If the thermal dynamic response of the building
~~component is to be determined, graduate level training in mathematics is needed.~~
~~5.29.4 Portable Calorimeter~~
~~Principle and Applications~~
~~The portable calorimeter is essentially a guarded hot box and is used~~
for measuring in situ heat transmission through building components. It was developed by the Building Research Division of the National Research Council of Canada [5], The calorimeter is an insulated box having five sides; the open
~~side is sealed against the inside surface of the building envelope component~~
~~for which heat transmission tests are to be performed. The temperature inside~~
~~the box is kept equal to the indoor temperature of the building enclosure by means of a thermostatically controlled electric heater. The electric~~
~~106 energy supplied to the electric heater is essentially equal to the heat~~
transmission through the metered area since the reverse heat loss through the box and edge loss where the box edge contacts the metered surface are essentially nulled to zero [5], This technique has the advantages that it provides a minimum disturbance to the measured heat transmission and a sufficiently large surface area is metered so that the measurements are representative of the performance of a building component. It is reported
~~that the accuracy of the technique is about 5 percent [5].~~
~~Limitations~~
~~Calorimeter measurements should be conducted only during periods when the outdoor to indoor temperature difference (AT) is greater than 10° F.~~
Solar heating of walls in the winter season may frequently produce AT less than 10° F. During the measurement of heat transmission through building components, the indoor temperature must be thermostatically controlled at a constant level in order to minimize differences in temperature between the calorimeter and the room. Also, solar radiation into the building and conditioned air from a warm air supply must not be permitted to strike the calorimeter. Only qualified technicians experienced with this technique and also having an understanding of the fundamentals of building heat transfer should carry out this procedure.
~~5.29.5 Spot Radiometer~~
~~Description of Method~~
~~Spot radiometers can be used to determine qualitatively whether a wall or other building component is insulated or if insulation voids or other~~
~~thermal defects are present. They are hand-held devices used to~~
~~107 radiometrically measure the equivalent blackbody temperature of a relatively~~
~~small area of a surface [5], Spot radiometers are generally small, light weight, and most are gun-shaped. They are calibrated by pointing them at a~~
~~surface of known temperature and adjusting a meter so that the device~~
~~radiometrically determines the correct temperature of the reference surface.~~
~~Manufacturers often provide reference surfaces having approximately black body characteristics (i.e., reflecting little radiation from surrounding~~
surfaces) for calibration purposes. Interior surfaces of buildings generally have emittances which range from about 0.80 to 0.95. Since the emittance of an interior wall surface to be measured may differ from the reference surface,
~~the apparent surface temperature determined using a spot radiometer may differ from the actual surface temperature by a small amount [5].~~
~~In using the spot radiometer, it is pointed at the surface for which~~
~~temperature is to be measured and the on-off trigger is depressed. The device~~
~~senses the total infrared radiation over a particular wavelength band emanating~~
~~from the surface, including both the self-emitted surface radiation and~~
~~reflected radiation from surrounding surfaces. The device is calibrated to~~
~~read the apparent radiance temperature on either a digital or meter display.~~
~~The apparent radiance temperature is defined as the temperature of a perfectly black surface (emittance =1) which would radiate the same amount of thermal~~
~~radiation as the self-emitted and reflected radiation emanating from the~~
~~real surface at its actual temperature and having a surface emittance different~~
~~from unity. The devices generally have their principal spectral response~~
~~in the range of 10 microns, and a response time less than 2 seconds. Contact~~
~~with the surfaces to be measured is not necessary with these devices.~~
~~Operation close to a wall or building component will indicate apparent surface~~
108 temperature of a small region, while operation at a distance will indicate apparent surface temperature for a larger region. Spot radiometers may be equipped with an audio device that will produce a change in audible tone when a thermal anomaly such as an air infiltration path or missing insulation is found while scanning a wall or building component. Gross thermal defects can be readily detected while quickly scanning the envelope of a building.
~~Limitations~~
~~This technique is not sensitive enough to permit detection of small diffrences in effectiveness of insulation such as to distinguish an R-13 wall from an R-15 wall.~~
~~5.30 Ultrasonic Pulse Methods~~
In the ultrasonic pulse methods, sound waves which are beyond the audible range are induced in a test object by a piezoelectric transducer, and either reflected waves or those passing through the object are detected by a similar type of transducer [2,10,60-63]. When reflected waves are detected, the technique is called "pulse-echo," and the transmitting transducer may also act as the receiver. Waves passing through the object are detected with a second transducer, i.e., a receiving transducer.
Ultrasonic inspection is based on two principles: (1) the velocity of the acoustic waves in a material is a function of that material's elastic constants and density; and (2) when an acoustic wave encounters an interface between dissimilar materials, a portion of the wave is reflected. The amount of reflection depends on the mismatch in acoustic impedance (product of wave velocity and density) of the materials, with the amount of reflection increasing with the mismatch.
~~109 .~~
~~5.30.1 Ultrasonic Pulse Velocity~~
~~The ultrasonic pulse velocity method is one of the most universally used~~
~~NDE methods for assessing the quality of concrete.~~
~~Principle of Method~~
The ultrasonic pulse velocity method measures the travel time of an ultrasonic pulse passing through a material. The pulse generated by an electroacoustic transducer is picked up by a receiver transducer and in some cases the pulse may be amplified. The time of travel of the pulse is measured electronically [63].
When a mechanical pulse is applied to a material by an electroacoustic transducer, waves are induced in the material. Longitudinal waves are used most often in testing concrete. These waves are transmitted by particles vibrating parallel to the direction of propagation. The waves' velocity, controlled by the elastic properties and the density of the material, is virtually independent of the geometry of the object being tested.
If a longitudinal wave encounters a discontinuity such as crack or void, it may "bend," i.e., be diffracted around the discontinuity. This increases the internal distance the wave must pass between the transmitting and pickup transducers, and consequently its travel time increases. The travel time of a longitudinal wave will also be affected by changes in density and elastic properties of a given concrete along the travel path.
~~Several ultrasonic pulse velocity units are commercially available for testing concrete; these cost about $4000. Some models can be used to test concrete as thick as 75 ft (30 m)~~
~~110 Application for Assessment of Condition of Concrete~~
The ultrasonic pulse velocity method Is best for nondestructive evaluation of the uniformity of in-place concrete. (ASTM Standard C 597 gives the standard test procedure, see Appendix D). For example, velocity measurements have been successfully used to detect deteriorated regions In concrete bridges and to check the uniformity of concrete in walls. In general, if substantial variations in pulse velocities are found in a structure, without any apparent reason (such as intentional changes in materials, concrete mix, or construction procedures), this indicates that the concrete is unsound.
A general rating which has been proposed to assess the relative quality of concrete is presented in Table 15 [64]. These criteria should be used with caution because differences in the qualities of concrete cannot be as sharply delineated as indicated in Table 15. In addition, velocity is affected by the density and amount of aggregate in the concrete. A crude assessment of the quality of similar types of concrete can be made, however, using these criteria. For example, if one concrete has a pulse velocity of 15,000 ft/sec
~~(4570 m/sec) , while another concrete with a similar composition has a velocity below 10,000 ft/sec (3050 m/sec), then there is clearly a significant difference in their qualities.~~
~~Table 15~~
~~Pulse Velocities in Concrete [64]~~
~~Feet per Second (Meters per Second) General Condition~~
~~Above 15,000 (4570) Excellent 12,000-15,000 (3660-4570) Good 10,000-12,000 (3050-4570) Questionable 7,000-10,000 (2130-3050) Poor Below 7,000 (2130) Very Poor~~
~~111 Estimation of Strength Properties of Concrete~~
Many investigations have attempted to correlate compressive and flexural strengths of concrete with pulse velocity [63]. Some correlations have been obtained in laboratory studies, provided that mix proportions, the cement, types of aggregate, and curing conditions were not varied. If these factors were altered, however, no usable correlations were obtained. For example,
Parker [65] compared pulse velocities and compressive strengths for concretes made from only one type of aggregate, but containing different cements from different sources and a variety of admixtures. His analysis of the data indicates that at the 95 percent confidence level the estimated strength of
~~4440 psi (30.7 MPa) concrete ranged from about 2100 to 6000 psi (14.5 to 41.8~~
~~MPa). Obviously, the ultrasonic pulse method cannot be used to obtain reliable estimates of compressive strength when the composition of concrete in a structure is unknown.~~
Jones has offered these concluding remarks regarding strength prediction from wave propagation methods: "In spite of some of the promising results of the early investigations, it must be concluded that no general relation has been found between the dynamic modulus of elasticity and its flexural or compressive strength" [66]. This statement still holds if one substitutes "pulse velocity" for "dynamic modulus of elasticity."
~~Extraneous Effects on Velocity Measurements~~
The measurement of the pulse velocity of concrete is affected by several factors which are not intrinsic properties of concrete, and, therefore, are not a function of the quality or strength of concrete [10], These factors include:
112 1, Smoothness of concrete at transducer contact area. Good acoustical contact between the transducers and concrete is required. In addition, a coupling agent such as an oil or a jelly must be used.
~~2. Concrete temperatures outside the range between Al° and 86°F (5° and~~
~~30° C) affect the measured pulse velocity. Below this temperature range, the velocity is increased, and above, the velocity is decreased.~~
~~3. Moisture condition of concrete. Pulse velocity generally increases as the moisture content of concrete increases, while compressive strength decreases as moisture content increases.~~
~~4, Presence of reinforcing steel. The pulse velocity in steel is 1.2 to~~
1.9 times the velocity in concrete. Measurements made near steel reinforcing bars, therefore, may not be representative of the concrete. If possible, measurements should be made perpendicular to the longitudinal axis of the bars.
~~If measurements must be made parallel to the longitudinal axis of the steel bars, crude correction factors are available.~~
~~5.30.2 Ultrasonic Pulse Echo~~
~~Principle of Method~~
In the ultrasonic pulse echo method, waves which are reflected off discontinuities (e.g., cracks and voids) and from interfaces (e.g., those between concrete and steel or between concrete and air) are recorded. Both the transmitting and receiving transducers are contained in the same probe; thus, only waves which are reflected back at nearly 180 degrees are detected.
The penetrating ability of the ultrasonic pulse and the minimum size of detectable flaws are influenced by the frequency of the generated waves. High frequency results in less penetration but better sensitivity than low frequency.
~~113 Applications~~
Echo techniques have been extensively used to identify and locate discontinuities and defects in metals and welds [2,60-62]. The echo technique is one of the most versatile and accepted NDE methods for metals. However, it has not been used often with concrete — largely because the extensive pore system, the presence of cracking, and the heterogeneous nature of concrete cause multiple reflections when very high frequency pulses are used. Therefore, the reflected waves are significantly attenuated and the interpretation of the observations complicated. As noted, the heterogeneous nature of concrete poses problems not encountered in pulse-echo evaluation of metals, thus, progress in this area of concrete nondestructive testing has been slow. A review of research indicates that the pulse-echo method has been used successfully to detect flaws within concrete, however, standardized methods do not currently exist for pulse-echo evaluation of concrete structures [67]. Pulse-echo methods have been used for detection of very large cracks in dams, for integrity testing of piles and other slender concrete structures, and for measuring the thickness of slabs and pavement. In addition, it may be possible to combine the echo method with acoustic impact (see Acoustic Impact Method,
Section 5.2) so that low frequency waves are generated. These would be insensitive to microscopic flaws but could be used to detect large discontinuities [68]. Commercial equipment is not yet available for such
~~testing.~~
~~Advantages~~
~~Ultrasonic pulse-echo inspection offers several advantages over other NDE methods — such as gamma radiography — capable of detecting internal flaws in~~
114 a test object [2]. For example, acoustic waves have excellent penetrating ability, and with proper Instrument selection, thick sections of 30 ft (10 m) or more can be inspected. Very small flaws may be detected, and their location and geometry estimated with reasonable accuracy. In addition, test results are immediately available and the equipment is lightweight and portable.
~~Limitations~~
Because of the indirect nature of flaw detection by ultrasonic pulse-echo inspection, personnel with a high level of expertise are needed to plan an inspection program. A thorough understanding of the nature of the interactions between the acoustic waves and different discontinuities is required in order to interpret test results properly. The physical testing, on the other hand, may be performed by technicians after proper training. Before ultrasonic inspection equipment can be used, calibration and referencing with standards must be performed; otherwise, test results have no meaning. The nature of the calibrations will depend on the particular inspection program.
~~5.31 Uplift Resistance~~
~~Description of Method~~
~~The resistance of built-up roofing systems to uplift pressure can be~~
~~determined using the ASTM Standard E 907 test method (Appendix D) . A controlled negative pressure is created on top of the roof surface using a chamber, 5 x 5 ft~~
~~(1.5 x 1.5 m) in area, fitted with a vacuum pump and a pressure measuring device.~~
Provisions must be made to provide a smooth surface along the roof to allow the edges of the chamber to be in complete contact with the roof surface so that a negative pressure can be applied inside the chamber. For roofs containing mineral
115 aggregate surfacing, the loose surfacing should be removed by sweeping a path about 12 in. (300 mm) wide and applying a heavy pouring of hot asphalt over the swept area. When the asphalt cools it will provide the smooth surface necessary for contact with the chamber. The bottom flanges of the chamber are equipped with a foam strip to seal the chamber to the roof surface. The chamber is oriented on the roof so that the edges are parallel with the direction of the structural framing of the building.
~~The negative pressure is applied in increments and the deflection is continuously monitored during the test for sudden or variable rates of movement.~~
The predetermined increments of pressure are held for 1 minute and further increments are applied until a preselected negative pressure is reached or failure (adhesion or cohesion) occurs. Most roof systems subjected to a negative pressure will exhibit an upward deflection that will increase with an increase in negative pressure. Poorly adhered roofing systems will exhibit relatively large increases in upward defections with relatively small increases in applied pressure. For well adhered roofing systems the increase in deflection will be gradual and at a relatively constant rate up to a point at or near failure.
~~5.32 Visual Inspection~~
Surface defects often can be detected visually using methods to improve ordinary observations. Optical magnification or other techniques which can be used to increase the apparent size of surface cracks are covered in this section.
~~5.32.1 Optical Magnification~~
~~Available magnifying instruments range from simple, inexpensive glasses to expensive microscopes. Some fundamental principles about the operating~~
116 characteristics of magnification instruments should be understood before a system is chosen for a particular application. For example, the focal length decreases as the magnification power increases. This means that when high magnification is desired, the primary lens must be placed close to the test object. The field of view (the portion of the object that can be seen at any instant) also decreases as magnification power increases. A small field of view means that it will be tedious to examine a large surface area. Another important characteristic is the depth of field — the elevation difference of rough textured surfaces that can be viewed in focus simultaneously; the depth of field decreases as the magnification power of the instrument increases.
~~Therefore, to inspect a rough-textured surface, a magnification power should be selected that gives a large enough depth of field so that the "hills" and~~
"valleys" are simultaneously in focus. Finally, the illumination intensity required to clearly see surface flaws will increase as the magnification power increases. High magnification may require a light source to supplement the available lighting.
A useful tool for field inspection is a pocket magnifier with a built-in viewing scale, which allows measurement of flaw dimensions. A stereomicroscope is very useful when a three-dimensional view of the surface is required. With
this instrument, one can determine whether a wide crack is shallow or extends deep into the object. If calibrated, a stereomicroscope can also be used as a depth gage to measure the approximate height of surface irregularities.
~~5.32.2 Fiberscope~~
~~Another useful instrument is the fiberscope, which is composed of a bundle~~
~~of flexible optical fibers and lens systems. The fiberscope can be inserted~~
117 through a small access hole so that the inside of a cavity can be seen. Some of the fibers in the bundle carry light into the cavity and illuminate the field of view. The viewing head can be rotated so that a wide viewing angle is possible from a single access hole. A fiberscope, because of the discrete nature of light transmission of the fibers, may not have as good resolution as a borescope, which is straight, rigid tube using a lens system for viewing. The best resolution is obtained with an instrument having small- diameter fibers in which the fiber density per unit area is high. To use a fiberscope, one must drill access holes if natural channels are not present, and the hole must intercept cavities. The acoustic impact technique
~~(Section 5.2) can be used to locate hollow spots for subsequent fiberscope inspection.~~
~~5.32.3 Liquid Penetrant Inspection~~
In this method a highly visible dye is used to coat the surface to be inspected [2,69]. Any cracks open to the surface will soak up the dye because of low surface tension and capillary effects. After application of the dye, the surface is cleaned. However, the dye which penetrated into cracks remains and reveals the presence of cracks. The method is one of the most inexpensive inspection tools, but it only permits detection of open flaws on the surface of the test object.
~~Description of Method~~
~~Dye penetrant inspection involves the following steps: (1) cleaning the surface, (2) applying the dye, (3) removing excess dye from the surface,~~
~~(A) applying a developer, and (5) interpreting the results.~~
118 The objective of the cleaning is to remove foreign matter from cracks so that the dye can penetrate. The specific procedures depend on the condition of the surface. Care must be taken to ensure that the cleaning process does not smear the cracks or fill them with residues. For example, sandblasting a soft metal may "hammer" the surface so much that cracks become closed and undetectable.
~~The dye may be applied to the surface by spraying, painting, or dipping.~~
Two types of dye are available: one is for viewing under ordinary light and is usually a brilliant red color, the other is fluorescent and viewed under ultraviolet light. Fluorescent dyes offer the best sensitivity for detecting small cracks. The dye is allowed to remain on the surface from 10 to 30 minutes
~~(dwell time) before the excess is removed.~~
Cleaning can be done by flushing the surface with water or by wiping with a rag dampened with solvent. An emulsifying agent is needed so that the dye can be completely removed with water. The agent is either already included in the dye, or it is added to the coated surface before washing. This phase is very important; all excess dye must be removed, otherwise some indications of cracks will be false. If the surface is very porous, inspection by this method may be difficult; if dye is not removed from the pores, there will be a loss of contrast because the surface will take on a color that is a light shade of the dye. If the dye is removed from all pores, it probably will be removed from some of the cracks as well.
~~After cleaning, the surface is allowed to dry, and a developer is added.~~
Developer is a fine powder which: (1) provides a uniform, colored background to increase contrast, and (2) has a blotting effect, thereby drawing up the dye from the cracks. The blotting action increases the apparent width of the
~~119 ,~~
cracks so that they are clearly visible. Developer can be applied as a dry powder or as a paint. The thickness of the developer layer is important; if it is too thin, there will not be good contrast, and if it is too thick, it may mask the cracks.
~~Finally, the prepared surface is inspected. If the application was done correctly, the cracks will be clearly shown.~~
~~However, the inspector needs to be familiar with the patterns associated with "irrelevant indications," i.e., patterns not from cracks but from other sources, such as improper cleaning.~~
~~Applications and Limitations~~
Although dye penetrant inspection relies on simple principles, a certain amount of skill is necessary to carry out do the process correctly. The operator needs to recognize what materials to use for a particular application, and to understand how the materials respond to different temperature conditions.
Portable kits are available with the various chemicals in aerosol cans, thus making field inspection possible. The technology is now geared primarily toward inspection of metals. The applicability of the procedures to masonry or concrete structures having surfaces of high porosity has not been demonstrated,
~~5.33 Water Permeability of Coated Masonry Walls~~
~~Principle and Applications~~
The transmission of water through coated masonry walls is proportional to the number of "pin holes" in the coating. The exterior coating and its application are the most significant variables in preventing excessive permeation into the masonry. A reservoir, about 7 in^ (12 x 10^ mm^) with an open face is sealed to the masonry and kept pressed against the wall
120 by a spring which is stretched between two hooks that are secured to the masonry wall. The reservoir is filled with water and the water is allowed to permeate the wall for 15 minutes or the time required to absorb 25 ml of water. The water absorbed by the wall is determined from a burette connected to the reservoir.
From a measurement of the diameter of the reservoir, the rate of water absorption can be expressed in gallons per square foot per hour. When the rate of water disappearance from the reservoir is less than 1 gal/ft^/h there are no damaging effects. In order to provide a margin of safety, a limit of 1/2 gal/ft^/h was established [70]. A properly coated masonry surface will have a water transmission rate of about one-tenth that amount.
~~5.34 Combinations of Nondestructive Evaluation Methods~~
While no single NDE method may be entirely satisfactory for predicting the strength or quality of material, combinations of methods which respond to different factors may give more definite information. The combined NDE approach has been developed mainly for evaluating concrete; therefore, only applications to concrete will be described.
~~The results of two methods can be combined in a linear equation of the form:~~
f^ = A(NDEp + B(NDE2) + C where f is the estimated compressive strength from the combined method, NDEi and NDE2 are the results of the individual methods, and A, B, and C are empirically determined constants.
~~Two combinations often used are the ultrasonic pulse velocity method and the measurement of the damping constant of concrete [71], and the ultrasonic pulse~~
~~121 velocity and pulse attenuation methods [72]. These combinations are essentially laboratory research techniques and therefore will not be discussed further.~~
The most popular combination has been the ultrasonic pulse velocity method and the rebound hammer [73]. This combination has been used primarily in Europe, with the most exhaustive studies being carried out by Facaoaru [74-77]. In this combined approach, measurements of ultrasonic pulse velocity and rebound number are made on in situ concrete. The pulse velocity and rebound number are substituted into a previously derived regression equation to predict compressive strength. It is generally believed that the multiple regression equation should give a more accurate estimate of compressive strength than either of the individual measurements alone.
For standard concrete mixes, Facaoaru has developed calibration charts from which the compressive strengths can be estimated when the pulse velocities and rebound numbers are known [74]. Correction factors have also been developed to be used in the case of nonstandard concrete mixes. This combined method has been used often in Romania to estimate the compressive strength of in situ concrete [74,76]. Based on his experiences, Facaoaru contends that the combined method offers the following accuracy in predictions of compressive strengths:
~~1. When composition is known and test specimens or cores are available for calibration purposes, accuracy is within 10 to 15 percent.~~
~~2. When only the composition of the concrete is known, accuracy is within 15 to 20 percent.~~
~~3. When neither the composition is known nor test specimens or cores are available, accuracy is within 20 to 30 percent [76],~~
This suggests that for case 3, the combined method gives no better prediction of the compressive strength than can be obtained by measuring only the ultrasonic I pulse velocity or only the rebound number; in case 2, the improvement is marginal.
~~122 Therefore, only when the concrete is well characterized is this combined method better than the individual nondestructive methods.~~
~~123 6 . SUMMARY~~
Nondestructive evaluation (NDE) methods for evaluating In situ construction materials and condition assessment of building components and systems were Identified and described. This report Is Intended to help
Inspectors and those Involved In condition assessment choose appropriate NDE methods for specific building materials, components, and systems. Important properties of building materials along with Important performance requirements for building components are listed, and appropriate NDE methods for determining these properties are recommended. In many cases the advantages and limitations for the NDE methods are presented. Potential NDE methods which may or may not require further research and development before they are ready for routine use were also identified and briefly described. In addition, ASTM standards for NDE methods for concrete and other building materials and components were identified.
In a related aspect of the study, current Navy practices relative to the use of NDE methods in the construction and service cycle of buildings and other structures were reviewed. This review was based on Navy reports and documents provided by the Naval Civil Engineering Laboratory (NCEL) and the
Naval Facilities Engineering Command (NAVFAC), and on discussions with NAVFAC personnel involved with buildings and structures problems where NDE methods are used for diagnostic purposes. Navy Guide Specifications were examined for required tests, both NDE and destructive, of in situ building materials and components. Twenty nine of the 239 Guide Specifications reviewed contained required NDE tests.
~~124 7 . ACKNOWLEDGMENTS~~
~~This study was sponsored by the Naval Civil Engineering Laboratory~~
~~(NCEL) , Port Hueneme California, and the Naval Facilities Engineering Command~~
~~(NAVFAC). The authors appreciate the support and assistance of Joseph Berke~~
~~(NCEL) and Melvin Hironaka (NCEL) who provided liaison between NCEL and~~
~~NBS. The authors also thank their NBS colleagues, James Pielert , Walter~~
~~Rossiter, and Leonard Mordfin who gave important review comments on this report. The authors acknowledge the excellent and extensive support of~~
~~Denise Herbert for typing the manuscript.~~
~~125 ,~~
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~~54. Mitchel, L.J. and Hoagland, G.G., "Investigation of the Impact-Type Concrete Test Hammer," Highway Research Board Bulletin 305 (1961), p. 14.~~
~~55. Williams, C.H. , "Investigation of the Schmidt Concrete Test Hammer," Miscellaneous Report No. 6-267, U.S. Army Engineering Waterways Experiment Station (1958).~~
56. Klieger, P., Discussion of P.H. Peterson and V.M. Stoll, "Relation of Rebound Hammer Test Results to Sonic Modulus and Compresslve- Strength Data," Proceedings of Highway Research Board, Vol. 34 (1955), p. 392.
~~57. Erickson, G.A. , "Investigation of the Impact-Type Concrete Test Hammer, Model II," Concrete Laboratory Report C-928, Division of Engineering Laboratories, Dept. of Interior (U.S.) (1959).~~
~~58. Manning, D.G. and Holt, F.B., "Detecting Delamination in Concrete Bridge Decks," Concrete International, Vol. 2, No. 11 (1980), pp. 34-41.~~
~~59. Grot, Richard A., Persily, Andrew K. , Chang, May Y. , Fang, Jin B.,~~
Weber, Stephen, and Galowin, Lawrence S. , "Evaluation of the Thermal Integrity of the Building Envelopes of Eight Federal Office Buildings," National Bureau of Standards (U.S.), NBSIR 85-3147 (September 1985).
~~60. Smith, A.L. , "Ultrasonic Testing Fundamentals," Lesson 5, Fundamentals of Nondestructive Testing, Metals Engineering Institute (1977).~~
~~61. Lovelace, J.F. , "Ultrasonic Testing Equipment," Lesson 6, Fundamentals of Nondestructive Testing, Metals Engineering Institute (1977).~~
~~130 62, Moberg, A.J. , "Ultrasonic Testing Applications," Lesson 7, Fundamentals of Nondestructive Testing, Metals Engineering Institute (1977).~~
~~63, Whltehurst, E.A., "Evaluation of Concrete Properties from Sonic Tests," American Concrete Institute, Monograph No. 2 (1966),~~
64, Leslie, J,R, and Cheesman, W.J. , "An Ultransonlc Method fo Studying Deterioration and Cracking In Concrete Structures," Journal of the American Concrete Institute, Vol. 21, No. 1 (19A9), Proceedings, Vol. 46, pp. 17-36,
~~65, Parker, W.E,, "Pulse Velocity Testing of Concrete," Proceedings of the American Society for Materials and Testing, Vol, 53 (1953), p. 1033.~~
~~66, Jones, R, , "Nondestructive Testing of Concrete," Cambridge University Press (1962),~~
~~67, Carlno, N.J, and Sanalone, M, , "Pulse-Echo Methods for Flaw Detection in Concrete," National Bureau of Standards (U,S.), Technical Note 1199 (July 1984).~~
68, Sansalone, Mary and Carlno, Nicholas J., "Transient Impact Response of Plates Containing Flaws," Journal of Research of the National Bureau of Standards (U,S.), Vol. 92, No. 6 (November-December 1987), pp. 369-381,
~~69, Lomerson, E.G., "Liquid Penetrants," Lesson 2, Fundamentals of Nondestructive Testing, Metals Engineering Institute (1977).~~
~~70, Naval Civil Engineering Laboratory Techdata Sheet 75-31, "Measuring Water Permeability of Masonry Walls," Port Hueneme, G (December 1975).~~
~~71, Wiebenga, J.G. , "A Comparison Between Various Combined Nondestructive Testing Methods to Derive the Compressive Strength of Concrete,"~~
~~Report No. Bl-68-61/ IHI.8 , In Situ TNG Voor Bouwmaterlalen en Bouw Constructies, Delft, Netherlands (1968).~~
~~72, Galan, A., "Estimate of Concrete Strength by Ultrasonic Pulse Velocity and Damping Constant," Journal of the American Concrete Institute, Vol, 64, No. 10 (1967), p. 678.~~
~~73, Jones, R. and Facaoaru, I., "Analysis of Answers to a Questionnaire on the Ultrasonic Pulse Technique," Materlaux et Constructions/Materials and Structures, Vol. 1, No. 5 (1968), p. 457.~~
~~74, Facaoaru, I,, "Nondestructive Testing of Concrete in Romania," Paper 4C, Symposium on Nondestructive Testing of Concrete and Timber, London, Institution of Civil Engineers (1969).~~
~~131 75. Facaoaru, I., Dumitrescu, I. and Constaninescu, L. , "Concrete Strength Determination by Nondestructive Combined Methods," RILEM Report, Aachen, 41 (1966).~~
~~76. Facaoaru, I., Dumitrescu, I. and Stamate, G.L. , "New Developments and Experience in Applying Combined Nondestructive Methods for Testing Concrete, RILEM Report, Varna, 26 (1968).~~
~~77. Facaoaru, I., "Chairman's Report of the RILEM Committee on Nondestructive Testing of Concrete," Materiaux et Constructions/Materials and Structures, Vol. 2, No. 10 (1969), p. 253.~~
~~132 APPENDIX A. REVIEW OF NAVY GUIDE SPECIFICATIONS~~
~~The Navy Guide Specifications that were reviewed with regard to NDE in situ tests of building materials and components are listed in Table A.~~
Twenty nine of the 239 Navy Guide Specifications listed in this table contained required NDE tests. The twenty-nine Guide Specifications along with the NDE tests required for each specification are given in Appendix B.
The tests included in the Guide Specifications are listed for each specification and they include field tests, laboratory tests, and NDE tests. Some of the field tests and laboratory tests are of the destructive type.
~~A-1 2~~
~~Table A. Review of Navy Guide Specifications~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~1. TS-T18 a Specification for Timber Harvesting (July 1965) No tests specified~~
~~2. NFGS-02050 Demolition and Removal (March 1984)~~
~~No tests specified~~
~~3. NFGS-02102 Clearing and Grubbing (August 1982)~~
~~No tests specified~~
~~4. TS-02200 Earthwork Amendment-l (November 1980)~~
~~Field Tests NDE Tests~~
• gradation of fill None specified or backfill material • liquid limit and plasticity of fill or backfill material • moisture density relationship of fill or backfill material • density of in place material • moisture content of in place soil material (ASTM D 3017)
~~5. NFGS-02247 Portland Cement Stabilized [Base] [or] (March 1983) [Subbase] Course for Airfields, Roads and Streets~~
~~Tests NDE Tests~~
• aggregate or existing None specified soil aggregate materials -sieve analysis of combined material -liquid limit -plasticity index • compressive strength of cement treated materials • smoothness of paved area • thickness of base or subbase course
~~A- 3~~
~~Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~• field density • laboratory tests -optimum moisture content and maximum density -moisture-density relationship of existing soils (for site preparation)~~
~~6. NFGS-02250 Soil Treatment for Subterranean (June 1981) Termite Control~~
~~No tests specified~~
~~7. NFGS-02361 Round Timber Piles (July 1983)~~
~~Tests NDE Tests~~
~~• load test of piles None specified~~
~~8. TS-02362.3 Auger-Placed Grout Piles (October 1980)~~
~~Tests NDE Tests~~
~~• load tests of piles None Specified • grout consistency (flow cone test) • grout compressive strength~~
~~9. NPGS-02363 Cast-ln-Place Concrete Piling, Steel (August 1981) Casing~~
~~Tests NDE Tests~~
~~• load tests of piles None specified • concrete testing~~
~~10. NFGS-02367 Prestressed Concrete Piling (August 1981)~~
~~Tests NDE Tests~~
~~• load tests of piles None specified • concrete testing (aggregates, compressive strength of concrete)~~
~~A- Table 4. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~11. TS-02360.1 Round Timber-Concrete Composite Piles (October 1980)~~
~~Tests NDE Tests~~
~~load tests of piles None specified~~
~~12. TS-02368 Steel H-Piles (January)~~
~~Tests NDE Tests~~
~~• load tests of piles None specified~~
~~13. NPGS-02369 Pressure- Injected Footings (March 1984)~~
~~Tests NDE Tests~~
~~• load tests of footings, None specified measure deflection or settlement~~
~~14. NFGS-02369.1 Sheet Steel Piles (September 1983)~~
~~No tests specified~~
~~15. NFGS-02452 Railroad Trackwork (September 1984)~~
~~Tests NDE Tests~~
~~• verify gauge, alignment, and • ultrasonic inspection of surface elevation of track welded rail joints~~
~~16. NFGS-02485 Turf (December 1982) No tests specified~~
~~17. NFGS-02490 Trees, Plants, and Ground Cover (November 1982)~~
~~No tests specified~~
~~A-4 5~~
~~Table 4. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~18. TS-02513.1 Asphalt Concrete Base Course (September 1979) (Central Plant Hot Mix)~~
~~Tests of Pavement Course NDE Tests~~
~~• density using cores None specified • thickness • straightedge of compacted surface~~
~~19. NPGS-02559 Portland Cement Concrete Pavement (October 1983) for Roads and Air Fields~~
~~Tests at job site NDE Tests~~
• slump None specified • air content • temperature of plastic concrete In-place • surface smoothness • pavement thickness (core samples); note, cores can also be used to evaluate condition of the concrete • flexural strength (from job site beam specimens)
~~20. NFGS-02573 Bituminous Hot Mix Pavement (March 1984)~~
~~Tests NDE Tests~~
~~• density using cores None specified • thickness of binder and wearing courses • smoothness of compacted surfaces • finish grades of each course placed~~
~~21. NFGS-02576 Asphalt Slurry Seal September 1981~~
~~Tests NDE Tests~~
~~• slurry mixture None specified water content residual asphalt content gradation of extracted aggregate calculate percent of emulsified asphalt~~
~~A- Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~• trial application (demonstrate ability to apply slurry seal)~~
~~22. TS-02577 Pavement Markings (Airfields and (July 1980) Roads~~
~~Field Testing NDE Tests~~
~~None specified None specified~~
~~23. NFGS-02578 Rubber and Paint Removal from (August 1982) Airfield Pavements~~
~~Field Testing NDE Tests~~
~~• demonstrate rubber and None specified paint removal on 50 ft. long test area • recommended friction and texture testing after removal work~~
~~24. TS-02581 Rotary Drilled Water Well (September 1978)~~
~~Tests NDE Tests~~
~~• measure flow and drawdown None specified~~
~~25. TS-02614 Joints, Reinforcement and Mooring (January 1978) Eyes in Concrete Pavements~~
~~No tests specified~~
~~26. TS-02616 Resealing of Joints in Rigid Pavement (October 1979) No tests specified~~
~~27. NFGS-02622.1 Fiberglass Reinforced Plastic (FRP) Piping (for Petroleum Products)~~
~~Field Tests NDE Tests~~
~~• initial pneumatic test at a None specified pressure of 15 psig • second pneumatic test at a pressure of 50 psig~~
~~A-6 7~~
~~Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~• hydrostatic pressure test • hydrostatic cycle test of system • operational test of system • backfill density~~
~~28. TS-02671 Bituminous Tack Coat (September 1980) No tests specified~~
~~29. TS-02672 Bituminous Prime Coat (September 1980)~~
~~Tests NDE Tests~~
~~• sulfonatlon Index test for tar None specified • spot test for asphalt~~
~~30. TS-02673 Bituminous Seal Coat , Spray (September 1980) Application~~
~~Tests NDE Tests~~
~~• stripping test None specified • spot test~~
~~31. TS-02675 Coal Tar Seal Coat with Unvulanlzed (March 1979) Rubber~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~32. NFGS-02676 Fog Seal (February 1982) No tests specified~~
~~33. TS-02677 Bituminous Surface Treatment (August 1980) No tests specified~~
~~A- i~~
~~Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~3A. TS-02685 Select-Material Base Course for (October 1980) Rigid Pavement~~
~~Field Tests NDE Tests~~
~~• aggregate gradation None specified • smoothness of top layer • density of each layer of base course • thickness of base course~~
~~35. TS-02686 Graded Aggregate Base Course for (October 1980) Flexible Pavement~~
~~Field Tests NDE Tests~~
~~• aggregate gradation None specified • smoothness of top layer • density of each layer of base material • thickness of base course~~
~~36. NFGS-02696 Selected-Material Subbase Course (November 1981) for Flexible Pavement~~
~~Field Tests NDE Tests~~
~~• aggregate gradation None specified • smoothness of top layer • density of each layer • thickness of subbase course~~
~~37. NFGS-02714 Exterior Steam Distribution (July 1982)~~
~~Field Tests NDE Tests~~
~~• test system to demonstrate None specified i compliance with contract • before Insulation is applied, hydrostatically test each piping system~~
~~A-8 9~~
~~Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~38. TS-02722 Exterior Sanitary Sewer System (July 1980)~~
~~Field Tests NDE Tests~~
• straightness of pipelines and None specified gross deficiences • leakage • deflection of plastic pipelines • pressure test of the system • field tests for concrete (Section 03300, "Cast-in-Place Concrete") slump compressive strength (from job-site cylinders) temperature tests
~~39. NFGS-02734 Rotary-Drilled Water Well (March 1984)~~
~~Field Tests NDE Tests~~
~~• measure flow and drawdown None specified (pump test) • well plumbness and alignment~~
~~40. NPGS-02854 Railroad Track Work (March 1983)~~
~~Field Tests NDE Tests~~
~~• (visual) inspect new rail None specified fittings thoroughly (bolted joints and welds) • verify gage, alignment and surface elevation of track~~
~~41. NFGS-02881 Dredging (November 1981)~~
~~No tests specified~~
~~A- Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~42. TS-02886 Wood Marine Piling (August 1980)~~
~~Field Test NDE Tests~~
~~• load tests on piles None specified~~
~~43. NFGS-02891 Pier Timberwork (March 1982) No tests specified~~
~~44. NFGS-02910 Welding Crane and Railroad Rail- (November 1982) Thermite Method~~
~~Tests NDE Tests~~
• visual inspection of each • ultrasonic inspection of each welded joint welded joints • ultrasonic inspection of • hardness of the weld (6 in. on each welded joint each side of the joint) • hardness of the weld 6 in. on each side of joint (Brinell Hardness Number)
~~45. TS-03300 Cast-In-Place Concrete (June 1980)~~
~~Amendment-3 (February 1984)~~
~~Field Tests of Concrete NDE Tests~~
• slump None specified • ball penetration • compressive strength or flexural strength (from job site cylinders) • yield (when challenged by contracting officer) • temperature • aggregate sampling and testing for specified requirements
~~A-10 Table A. (Continued)~~
~~Guide Spec. No. & Date Guide Spec. Title~~
~~46. NFGS-03302 Cast- In-Place Concrete (April 1981) (Minor Building Construction)~~
~~Amendment-1 (February 1984)~~
~~No tests specified~~
~~47. NFGS-03361 Shotcrete (April 1985)~~
~~Field Tests NDE Tests~~
~~• visual inspection None specified • make test panel • compressive and flexural strength (cores and beams) • durability factor (from core) • air content~~
~~48. TS-03410 Precast Structural Concrete (December 1978) (Non-Pres tressed)~~
~~Testing at Casting Site~~
~~• slump • air content • unit weight for lightweight concrete • compressive strength (cylinders made at casting site, core testing required if compressive strength fails to meet requirements)~~
~~Other Requirements NDE Tests~~
~~• tolerances of finished products None specified • finished appearance~~
~~49. NFGS-03411 Precast Concrete Wall Panels (August 1981)~~
~~Testing at batch plant~~
~~• aggregate tests (mechanical analysis, including specific gravity) from samples • slump • compressive strength (cylinders made at plant)~~
~~A-11 Table A. (Continued)~~
~~Guide Spec. No. & Date Guide Spec. Title~~
~~Other Requirements NDE Tests~~
~~• tolerances of finished panels and None specified In Installation • finished appearances~~
~~50. TS-03420 Precast Prestressed Concrete (December 1978)~~
~~Testing at Casting site NDE Tests~~
~~• slump None specified • air content • unit weight of lightweight concrete • compressive strength (cylinders made at casting site)~~
~~Other Requirements~~
~~• tolerances of finished products • finished appearances • measurement of cracks In precast-prestressed concrete • camber~~
~~51. TS-03501 Insulating Concrete Roof Deck System (March 1979)~~
~~Field Tests (test specimens NDE Tests taken at job site)~~
~~• compressive strength None specified • oven dry density • coefficient of heat transmission~~
~~52. NFGS-04200 Unit Masonry~~
~~(November 1983)~~
~~No field tests specified~~
~~A-12 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~53. NPGS-04230 Reinforcing Masonry (July 1984)~~
~~Tests at Job-Site NDE Tests~~
~~• compressive strength of mortar None specified and grout • compressive strength of masonry prims • efflorescence (masonry units and for mortar)~~
~~54. NPGS-04250 [ceramic Glazed Structural Clay (November 1982) Facing Tile] [AND] [Prefaced Concrete Masonry Units]~~
~~No field tests specified~~
~~55. NFGS-05120 Structural Steel (August 1981)~~
~~Tests NDE Tests~~
~~• visual Inspection of welds • radiographic • test for embrlttlement of welds • ultrasonic • magnetic particle • dye penetrant~~
~~56. NFGS-05210 Steel Joists (December 1983)~~
~~No tests specified~~
~~57. NPGS-05311 Steel Roof Decking (May 1983)~~
~~Field Tests NDE Tests~~
~~• Inspect decking top surface for None specified flatness (straight edge)~~
~~58. TS-05321 Steel Floor Deck (September 1979)~~
~~Field Tests NDE Tests~~
~~visual inspection of welds None specified~~
~~A-13 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~59. NFGS-05400 Cold- Formed Metal Framing (August 1983)~~
~~No field tests specified~~
~~60. TS-05500 Metal Fabrications (November 1980)~~
~~No field tests specified~~
~~61 NFGS-07110 Membrane Waterproofing (April 1983)~~
~~Field Tests NDE Tests~~
~~sample bulk liquid asphalt None specified (conformance with specification requirements) watertightness (cover membrane waterpoofing horizontal surfaces with ponded water for 24 hours)~~
~~62 TS-07111 Elastomeric Waterproofing (September 1980) Sheet Applied~~
~~Field Tests NDE Tests~~
~~• watertightness of horizontal None specified surfaces of elastomeric waterproofing (cover with ponded water for 24 hours)~~
~~NDE Tests~~
~~None specified~~
~~63. TS-07120 Elastomeric Waterproofing (June 1980) System, Fluid Applied~~
~~Field Tests NDE Tests~~
• prior to application of fluid-applied None specified waterproofing, check moisture content of substrate using a moisture meter • check wet film thickness • watertightness, cover waterproofing with ponded water for 24 hours
~~A- 14 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~64. TS-07130 Bentonite Waterproofing (December 1980)~~
~~No field tests specified~~
~~65. NFGS-07140 Metallic Oxide Waterproofing (February 1983)~~
~~No field tests specified~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~66. NFGS-07160 Bituminous Dampprooflng (April 1983)~~
~~No field tests specified~~
~~67. NFGS-07211 Loose Fill (Celluloslc and (July 1981) Mineral Fiber) Insulation~~
~~No field tests specified~~
~~68. TS-07220 Roof Insulation (March 1980)~~
~~No field tests specified~~
~~69. NFGS-07221 Masonry Wall Insulation (November 1982)~~
~~No field tests specified~~
~~70. NFGS-07222 Tapered Roof Insulation (December 1982)~~
~~No field tests specified~~
~~71. NFGS-07232 Ceiling, Wall, and Floor (September 1981) Insulation~~
~~No field tests specified~~
~~A-15 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~72. NFGS-07250 Sprayed-on Fireproofing (February 1984)~~
~~Field Tests NDE Tests~~
~~• thickness None specified • density~~
~~73, NFGS-07310 Asphalt Shingles (August 1983)~~
~~No field tests specified~~
~~74. NFGS-07410 Preformed Metal [Roofing] [and] (May 1983) [Siding]~~
~~Factory tests to be conducted by manufacturer~~
~~salt spray • abrasion resistance for color coating f ormability • humidity test accelerated weathering • fire hazard chalking resistance • specular gloss color change~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~75. NFGS-07511 Aggregate Surfaced Bituminous Built-Up (June 1981) Roofing~~
~~Field Tests NDE Tests~~
~~• fastener resistance to pullout None specified • watertightness of roofing system (24 hour ponded water)~~
~~76. NFGS-07512 Smooth Surfaced Bituminous Built-Up (July 1981) Roofing~~
~~Field Tests NDE Tests~~
~~• fastener resistance to pullout None specified • watertightness of roofing system (24 hour ponded water)~~
~~A-16 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~77. NFGS-07520 Prepared Roll Roofing (February 1984)~~
~~Field Tests NDE Tests~~
~~• fastener resistance to pullout None specified~~
~~78. NFGS-07540 (August 1979) Silicone Rubber Roof Coating Amendment- 1 (June 1984)~~
~~Pages missing [only pages 1, 1.1, 4, and 8 f guide spec, are given)~~
~~79. NFGS-07545 Sprayed Polyurethane Foam (PUF) (July 1984) for Roofing Systems~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~80. TS-07600 (September 1978) Flashing and Sheet Metal Amendment-1 (June 1981)~~
~~[only Amendment-1 given]~~
~~81. NFGS-07920 Sealants and Calkings (August 1981)~~
~~No field tests specified~~
~~82. NFFGS-08110 Hollow Metal Doors and Frames (November 1981)~~
~~No field tests specified~~
~~83. NFGS-08120 Aluminum Doors and Frames (February 1984)~~
~~No field tests specified~~
~~84. NFGS-08129 Aluminum Storm Doors (July 1982)~~
~~No field tests specified~~
~~A-17 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~85. TS-08210 Wood Doors (February 1980)~~
~~No field tests specified~~
~~86. NFGS-08301 Steel Sliding Hanger Doors (November 1982)~~
~~Field Tests NDE Tests~~
~~• complete operating test of doors None specified~~
~~87. NFGS-08310 Sliding Fire Doors (March 1983)~~
~~No field tests specified~~
~~88. NFGS-08320 Metal- Clad (Kalamein) Doors and (March 1983) Frames~~
~~No field tests specified~~
~~89. NFGS-08331 Overhead Coiling Doors (March 1983)~~
~~No field tests specified~~
~~90. NFGS-08360 Overhead Metal Doors (July 1982)~~
~~Field Tests NDE Tests~~
~~• demonstrate proper installation, None specified and proper functioning of operators, safety features, and controls~~
~~91. NFGS-08367 Vertical Uft Metal Doors (July 1982)~~
~~No field tests specified~~
~~92. NFGS-08371 Aluminum Sliding Glass Doors (July 1983)~~
~~No field tests specified~~
~~A-18 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~93. TS-08510 Steel Windows (January 1980)~~
~~Field Tests NDE Tests~~
~~• steel windows to comply with None specified specified feeler gage tests~~
~~94. NFGS-08520 Aluminum Windows (June 1982)~~
~~No field tests specified~~
~~95. TS-08525 Storm Windows and Storm Doors (June 1978)~~
~~No field tests specified~~
~~96. NFGS-08529 Aluminum Storm Windows (July 1982)~~
~~No field tests specified~~
~~97. TS-08610 Wood Windows~~
~~(April 1980)~~
~~No field tests specified~~
~~98. NFGS-08710 Finish Hardware (March 1985)~~
~~No field tests specified~~
~~99. NFGS-08800 Glazing (December 1983)~~
~~No field tests specified~~
~~100. NFGS-09100 Metal Support Systems (February 1984)~~
~~No field tests specified~~
~~A-19 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~101. NPGS-09110 Lathing (August 1982)~~
~~No field tests specified~~
~~102. NFGS-09150 Plastering and Stuccoing (April 1981)~~
~~No field tests specified~~
~~103. TS-09215 Veneer Plaster (August 1979)~~
~~No field tests specified~~
~~104. NFGS-09250 Gypsum Board (March 1985)~~
~~No field tests specified~~
~~105. NFGS-09310 Ceramic Tile, Quarry Tile, (March 1984) and Paver Tile~~
~~No field tests specified~~
~~106. NFGS-09331 Chemical-Resistant Quarry (October 1983) Tile Flooring~~
~~Field Tests NDE Tests~~
~~• chemical resistance of mortar None specified and grout • water absorption of mortar • hardness of mortar • before tile is applied test structural floor for levelness and uniformity of slope~~
~~107. NFGS-09411 Terrazzo, Bonded to Concrete (September 1983)~~
~~No field tests specified~~
~~A-20 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~108. NFGS-09561 Gymnasium-Type Hardwood Strip (March 1984) Flooring Systems~~
~~No field tests specified~~
~~109. NFGS-09563 Portable (Demountable) Wood (July 1982) Flooring~~
~~No field tests specified~~
~~110. NFGS-09570 Wood Parquet Flooring (August 1983)~~
~~No field tests specified~~
~~HI. NFGS-09595 Wood Block Industrial Flooring (July 1983)~~
~~No field tests specified~~
~~112. TS-09661 Vinyl Composition Tile on (September 1980) Concrete~~
~~No field tests specified~~
~~113. NFGS-09666 Institutional Sheet Vinyl (February 1982) Flooring~~
~~Tests NDE Tests~~
~~• stain resistance of flooring material None specified • moisture test for concrete subfloor~~
~~114. TS-09670 Fluid Applied Resilient (January 1980) (Resinous) Flooring~~
~~Field Tests NDE Tests~~
~~• None specified None specified~~
~~115. NFGS-09682 Carpet (January 1983)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~A-21 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~116. NFGS-09690 Carpet Tile (July 1981)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~117. NPGS-09785 Metallic Type Conductive and Spark (April 1984) Resistant Concrete Floor Finish~~
~~Field Tests NDE Tests~~
~~• ground resistance of studs, rods, None specified and interconnecting ground wire • conductivity of finished floor surface • spark resistance of finished floor surface~~
~~118. TS-09804 Linseed Oil Protection of Concrete (January 1978) Surfaces~~
~~No field tests specified~~
~~119. TS-09805.1 Coating Systems ( Coal-Tar for Sheet (September 1979) Piling and Other Steel Waterfront Structures~~
~~Field Tests NDE Tests~~
~~thickness of coatings • holidays, pin holes and other holidays and pin holes in coatings defects/electrical flaw detector visual inspection of coatings~~
~~120. TS-09805.2 Coating Systems (Vinyl and Epoxy) (May 1980) for Sheet-Steel Piling and Other Steel Waterfront Structures~~
~~Field Tests NDE Tests~~
~~thickness of coatings holidays, pin holes and other holidays, pin holes, and other defects/electrical flaw detector defects in coatings visual inspection of coatings~~
~~A-22 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~121. NPGS-09815 High-Build Glaze Coatings (April 1981)~~
~~Field Tests NDE Tests~~
~~• dry film thickness/Tooke gage None specified~~
~~122. NPGS-09809 Protection of Burled Steel Piping (September 1981) and Steel Bulkhead Tie Rods~~
~~Field Tests NDE Tests~~
~~• test protective system for holes, • test with an electrical flaw voids, cracks, and other damage, detector visually~~
~~123. NPGS-09910 Painting of Buildings (Field Painting) (September 1981)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~124. NFGS-09951 Vinyl- Coated Wall Covering (August 1982)~~
~~Field Tests NDE Tests~~
~~• Test walls for moisture content None specified with an electric moisture meter~~
~~125. TS-10152 Hospital Cubicle Track (April 1980)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~126. NPGS-10162 Toilet Partitions (November 1982)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~A-23 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~127. NPGS-10201 Metal [Wall] [And] [Door] Louvers (January 1983)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~128. NFGS-10270 Access Flooring (July 1983)~~
~~Field Tests NDE Tests~~
~~• floor system electrical None specified resistance~~
~~129. NFGS-10440 Signs (March 1981)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~130. TS-10623 Accordion Folding (September 1979)~~
~~Field Tests NDE Tests~~
~~• Visual tests for light leakage None specified~~
~~131. NFGS-10800 Toilet and Bath Accessories (October)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~132. TS-11162 Fixed Type Industrial Dockboard (November 1980)~~
~~Field Tests NDE Tests~~
• visual inspection of welds • welds dye penetrant examined • proof-load dockboard • welds magnetic particle tested • drop tests on dockboard • low temperature environmental test of loading ramp • visual inspection of dockboard • roll over load test of dockboard
~~A-24 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~133. TS-11171 Incinerators, Packaged, Controlled- (October 1978) Air Type~~
~~Field Tests NDE Tests~~
• hydrostatic pressure of oil None specified (other than pneumatic piping systems (using oil) test) • pneumatical test of gas piping systems; soap bubbles to verify tightness of system • performance test of incinerator including controls • shell temperature (outer shell) of incinerator
~~134. TS-11301 Packed, Gravity Oil/Water Separator (April 1980)~~
~~Field Tests NDE Tests~~
~~• hydrostatic test of piping None specified • performance test of separator • test for contaminants in effluent~~
~~135. NPGS-11334 Comminutor (August 1982)~~
~~Field Tests NDE Tests~~
~~• performance test of coimninutor None specified~~
~~136. TS-11361.1 Rectangular Clarifier Equipment (September 1980)~~
~~Field Tests NDE Tests~~
~~• performance test of rectangular None specified clarifier mechanism~~
~~137. TS-11361.2 Circular Clarifier Equipment (September 1980)~~
~~Field Tests NDE Tests~~
~~• performance test of circular None specified clarifier mechanism~~
~~A-25 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~138. NFGS-11371 Trickling Filter (December 1982)~~
~~Field Tests NDE Tests~~
~~• performance test of distributor None specified mechanism~~
~~139. NFGS-11700 General Requirements for (April 1984) Medical Equipment~~
~~Field Tests NDE Tests~~
~~performance test of installed None specified equipment~~
~~140. NFGS-11701 Casework, Metal and Wood (June 1981) Medical and Dental~~
~~No field tests specified~~
~~141. TS-11702 Medical Equipment , Miscellaneous (July 1980)~~
~~Field Tests NDE Tests~~
~~• performance test of equipment None specified~~
~~142. NFGS-11704 [Casework, Movable and Modular for (April 1985) Laboratory and Pharmacies] [And] [Materials Handling Units] for Medical Facilities~~
~~No field tests specified~~
~~143. TS-11720 Stills and Associated Equipment (September 1980)~~
~~Field Tests NDE Tests~~
~~• performance test of water None specified distilling apparatus~~
~~A-26 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~144. TS-11722 Sterilizers and Associated Equipment (September 1980)~~
~~Field Tests NDE Tests~~
~~• performance test of equipment None specified~~
~~145. TS-11730 Washing Equipment (September 1980)~~
~~Field Tests NDE Tests~~
~~• performance test of equipment None specified~~
~~146. TS-11744 Dental Equipment (August 1980)~~
~~Field Tests NDE Tests~~
~~• performance test of equipment None specified~~
~~147. NFGS-11757 Radiographic Darkroom Equipmen t (August 1981)~~
~~Field Tests NDE Tests~~
~~• performance test of equipment None specified~~
~~148. TS-11770 Government-Furnished and Contractor (August 1980) Installed Existing Medical Equipment~~
~~Field Tests NDE Tests~~
~~• insure equipment is None specified operational~~
~~149. NFGS-12322 Wardrobes (August 1982)~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~150. NFGS-12331 Prefabricated Vanities (March 1985)~~
~~No field tests specified~~
~~A-27 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~151. NFGS-12332 Wardrobe Storage Cabinets (March 1985)~~
~~No field tests specified~~
~~152. TS-12391 Kitchen Cabinets [and Vanity (January 1981) Cabinets]~~
~~No field tests specified~~
~~153. NFGS-12510 Blinds, Venetian (and Audio Visual) (April 1981)~~
~~Field Tests NDE Tests~~
~~• test for light Intensity None specified~~
~~154. NFGS-12540 Draperies (July 1984)~~
~~No field tests specified~~
~~155. NFGS-12711 Theater Seating (February 1984)~~
~~No field tests specified~~
~~156. TS-13092 X-Ray Shelldlng~~
~~Field Tests NDE Tests~~
~~• Visual inspection None specified~~
~~157. NFGS-13121 Pre-englneered Metal Buildings (October 1983) Rigid Frame)~~
~~Field Tests NDE Tests~~
~~• sample panels tested for con- None specified formance to specified requirements [salt spray, accelerated weathering, flexibility, adhesion (film)]~~
~~A-28 Table A. (Continued)~~
~~Guld^ Spec. No & Date Guide Spec, Title~~
~~158. NFGS-13411 Water Storage Tanks (June 1981)~~
~~No field tests specified~~
~~159. NFGS-13625 Flow Measuring Equipment (Sewage (February 1982) Treatment Plant)~~
~~Field Tests NDE Tests~~
~~• test in-place the flow None specified measuring equipment to demonstrate it meets the accuracy requirements~~
~~160.. NFGS-13657 Cleaning Petroleum Storage Tanks (March 1983)~~
~~Field Tests NDE Tests~~
~~• lead-in-air tests None specified (after cleaning)~~
~~161. NFGS-13661 Fiberglass Reinforced Plastic Lining (August 1981) System for Bottotns of Steel Tanks (for Petroleum Fuel Storage)~~
~~Field Tests NDE Tests~~
• test panels, steel plate, • holiday detector test of lining for sand blast for use as standard of comparison • air inhibition test (for evidence of undercure of lining) • fill test (for leakage of tank)
~~162. TS-13765 Radio Frequency Shielded Enclosures, (April 1979) Demountable Type~~
~~Field Tests NDE Tests~~
~~• door sag test • seam leak detector testing • attentuation testing (shielding), "sniffer" (RF shielded enclosures) • door static load test~~
~~A-29 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~163. TS-13766 Radio Frequency Shielded Enclosures, (April 1979) Welded Type~~
~~Field Tests NDE Tests~~
• swinging door static load test seam leak detector testing of • swinging door sag test welds, "sniffer" • sliding and swinging door closure test • attenuation testing • visual Inspection of welds
~~164. NFGS-13947 Energy Monitoring and Control System (August 1983) (EMCS) Large System Configuration~~
~~No field tests specified~~
~~165. NFGS-13948 Energy Monitoring and Control System (August 1983) (EMCS) Medium System Configuration~~
~~No field tests specified~~
~~166. NFGS-13950 Energy Monitoring and Control System (August 1983) (EMCS) Micro System Configuration~~
~~No field tests specified~~
~~167. TS-13981.1 Solar Energy Systems Flat Plate (March 1980) Collectors (Liquid Type)~~
~~Field Tests NDE Tests~~
~~• hydrostatic testing None specified • pneumatic testing • start-up and operational tests~~
~~A-30 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~168. TS-14200 Electric [Passenger] [Freight^ (May 1980) Elevator~~
~~Field Tests NDE Tests~~
~~• operational tests None specified • speed load tests • temperature rise tests (motor, etc) • car leveling tests • brake test • insulation (electrical) resistance tests • buffer tests~~
~~169. NFGS-14214 Hydraulic [Passenger] [Freight^ (February 1984) Elevator~~
~~Field Tests NDE Tests~~
~~• operational tests None specified • speed load tests • car leveling tests • stop test • pressure test (pump and cylinder head) • insulation (electrical) resistance tests~~
~~170. NPGS-14304 Portal Crane Track Installation (January 1984)~~
~~Field Tests NDE Tests~~
• grout compressive strength • ultrasonic inspection of welded • visual inspection (fittings, rail joints bolted joints, welds) • as-built survey • load test of trackage and curve • throw mechanism operational test
~~A-31 Table A. (Continued)~~
~~Guide Spec, No & Date Guide Spec. Title~~
~~171. TS-14305 Fabricated Portal Crane Track (February 1980) Switches and Frogs~~
~~Field Tests NDE Tests~~
~~• operational tests None specified • tolerances (vertical movement) • joint mismatch tolerances (vertical, horizontal) • joint gap tolerance~~
~~172. NFGS-14334 Monorails with Manual Hoist (March 1983)~~
~~Field Tests NDE Tests~~
~~• operational iqspection and tests None specified~~
~~173. NFGS-14335 Monorails with Air Motor Powered (April 1982) Hoist~~
~~Field Tests NDE Tests~~
~~• operational inspection and tests None specified~~
~~174. NFGS-14336 Cranes, Overhead Electric, (January 1982) Overrunning Type~~
~~Field Tests NDE Tests~~
~~• operational inspection and tests None specified~~
~~175. NFGS-14637 Cranes, Overhead Electric, Underrunning (July 1984) (Under 20,000 pounds)~~
~~Field Tests NDE Tests~~
~~• operational inspection and None specified tests~~
~~176. NFGS-15011 Mechanical General Requirements (February 1981)~~
~~No field tests specified~~
~~A-32 Table A. (Continued)~~
~~Guide Spec, No & Date Guide Spec. Title~~
~~177. NFGS-15116 Welding Pressure Piping (July 1982)~~
~~Field Tests NDE Tests~~
• Visual Inspection of welds NDE personnel shall be certified as qualified radiographic examination of welds liquid penetrant examination of welds magnetic particle examination of welds ultrasonic examination of welds
~~178. TS-15200 Noise, Vibration, and [Seismic] (September 1979) Control~~
~~Field Tests NDE Tests~~
• check for vibration and noise None specified transmission through connections, piping duct work, foundations, and walls • vibration tests for conformance with criteria • sound level tests for conformance with criteria
~~179. NFGS-15251 Insulation for Exterior Piped (January 1984) Utilities~~
~~Field Tests NDE Tests~~
~~None specified None specified~~
~~180. TS-15301 Exterior Sanitary Sewer and Drainage (December 1978) System Piping~~
~~Field Tests NDE Tests~~
~~• leakage tests None specified • alignment of pipeline~~
~~A-33 )~~
~~Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~181. TS-15355 Fuel Gas Piping (October 1980)~~
~~Field Tests NDE Tests~~
~~• metal welding or brazing inspection None specified • PE Fusion welding inspection • pressure test piping system • operational tests for conformance with criteria~~
~~182. NFGS-15361 Carbon Dioxide Fire Extinguishing (January 1984) Systems (High Pressure)~~
~~Field Tests NDE Tests~~
~~• acceptance tests None specified • pneumatic test (leakage)~~
~~183. NFGS-15362 Carbon Dioxide Fire Extinguishing (January 1984) Systems (Low Pressure)~~
~~Field Tests NDE Tests~~
~~• pneumatic test (leakage) None specified • acceptance tests (conformance with specified requirements)~~
~~184. NFGS-15365 Halon 1301 Fire Extinguishing (February 1984) System~~
~~Field Tests NDE Tests~~
~~• pneumatic test (leakage of system) None specified • acceptance and opeational tests of system~~
~~185. TS-15388 Screening Equipment (Sewage) (October 1973)~~
~~No field tests specified~~
~~186. TS-15390 Aeration Equipment ( Sewage (May 1972)~~
~~No field tests specified~~
~~A-34 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~187. TS-15395 Sludge Digestion Equipment (October 1973)~~
~~No field tests specified~~
~~188. TS-15399 Package Rotating Biological Con- (March 1979) tractor Wastewater Treatment Unit~~
~~Field Tests NDE Tests~~
~~• cathodlc protection Inspection None specified • pressure test each pipeline • acceptance and operational tests of system for conformance to specified requirements~~
~~189. NFGS-15400 Amendment-1 Plumbing (September 1983)~~
~~No field tests specified~~
~~190. NFGS-15403 Nonflammable Medical Gas Systems (March 1981)~~
~~Field Tests NDE Tests~~
~~• leak tests of systems None specified • equipment pressure tests of joints • vacuum tests~~
~~191. NFGS-15411 Compressed Air Systems (Non- (July 1983) Breathing Air Type)~~
~~Field Tests NDE Tests~~
• visual Inspection of welds • NDE personnel shall be certified • destructive tests of welds • radiographic (for welds) • hydrostatic and leak tightness • liquid penetrant (for welds) tests of system • magnetic particle (for welds) • operational tests
~~A-35 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~192. NFGS-15460 Hospital Plumbing Fixtures (July 1984)~~
~~Field Tests NDE Tests~~
~~• operational and acceptance tests None specified~~
~~193. TS-15502 Fire Extinguishing Sprinkler (October 1980) Systems (Dry Pipe)~~
~~Field Tests NDE Tests~~
~~• hydrostatic pressure test of system None specified • acceptance and operational tests~~
~~194. NFGS-15540 Fire Pumps (February 1982)~~
~~Field Tests NDE Tests~~
~~• hydrostatic pressure tests None specified • acceptance and operational tests~~
~~195. TS-15609 Aviation Fuel Distribution Systems (April 1978)~~
~~Field Tests NDE Tests~~
~~hydrostatic pressure tests of None specified piping systems acceptance and operational tests~~
~~196. NFGS-15612 Gas Distribution System (April 1984)~~
~~Field Tests NDE Tests~~
~~• visual inspection of welds • electrical holiday detector for • piping strength and tightness discontinuities in pipe coatings (pressure test)~~
~~A-36 1~~
~~Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~197. NPX;S-15631 Steam Boilers and Equipment (September 1981) 500,000 - 18,000,000 Btu/h)~~
~~Field Tests NDE Tests~~
• acceptance and operational tests None specified for compliance with contract requirements • strength and tightness (hydrostatic test) • pneumatic tests (air casing and ducts) • combustion tests • capacity and efficiency tests
~~198. NFGS-15632 Steam Boilers and Equipment (September 1981) 18,000,000 - 60,000,000 Btu/Hr Input)~~
~~Field Tests NDE Tests~~
• acceptance and operational tests None specified for compliance with contract requirements • strength and tightness (hydrostatic test) • pneumatic tests (air casing and ducts) • combustion tests • capacity and efficiency tests • steam tests
~~199. NFGS-15651 Refrigerant, Chilled Water, (January 1983) Condenser Water, Hot and Cold Water (Dual Service) Piping~~
~~Field Tests NDE Tests~~
~~• tightness of system None specified • pressure test (refrigerant system) • operational tests~~
~~200. TS-15652 Central Refrigeration System for Amendment- Air Conditioning (July 1982)~~
~~No field tests specified~~
~~A-37 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~201. NFGS-15653 Unitary Air Conditioning Systems (June 1984)~~
~~Field Tests NDE Tests~~
~~• operational tests • leak testing (electronic type • sound tests detectors)~~
~~202. NFGS-15707 [Factory Insulated] Glass Fiber (September 1981) Reinforced Plastic (FRF) Pipe Coondensate Return System~~
~~Field Tests NDE Tests~~
~~• hydrostatic pressure test of None specified system • operational test • moisture-density test of backfill • In-place compaction test~~
~~203. NFGS-15711 Hot Water Heating System (March 1981)~~
~~Field Tests NDE Tests~~
~~• strength and tightness None specified (hydrostatic test) for boiler and piping system • combustion test • operational test • capacity and efficiency test~~
~~204. NFGS-15721 Steam System and Terminal Units (March 1981)~~
~~Field Tests NDE Tests~~
~~• hydrostatic pressure test of None specified piping system • operational test~~
~~205. TS-15802 Air Supply Systems (November 1972)~~
~~Note: The last part of this specification was missing~~
~~A-38 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~206. TS-15813 Warm Air Heating Systems (October 1980)~~
~~Field Tests NDE Tests~~
~~• operational test None specified • fire test • duct test~~
~~207. TS-15820 Air Handling and Distribution Equipment (September 1980)~~
~~Field Tests NDE Tests~~
~~• operational test None specified~~
~~208. TS-15822 Evaporative Cooling System (October 1980)~~
~~Field Tests NDE Tests~~
~~• operational test None specified~~
~~209. NFGS-15840 Ductwork and Accessories (November 1982)~~
~~Field Tests NDE Tests~~
~~• operational test None specified • pressure tests for air leakage (ducts, plenums, and casings)~~
~~210. TS-15852.2 Duct Collector, Electrostatic Precipitation (May 1980) Type (Flue Gas Particulates)~~
~~Field Tests NDE Tests~~
~~• operational test None specified~~
~~211. NFX;S-15852.3 Duct Collector, Fabric Filter Type (January 1983) (Fly Ash Particles in Flue Gas)~~
~~Field Tests NDE Tests~~
~~• operational test None specified~~
~~A-39 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~212. TS-15901 Space Temperature Control Systems (August 1980)~~
~~Field Tests NDE Tests~~
~~• operational test None specified~~
~~213. TS-16011 General Requirements, Electrical (November 1978)~~
~~No field tests specified~~
~~214. NFGS-16113 Underfloor Raceway System (February 1984)~~
~~Field Tests NDE Tests~~
~~• electrical continuity test None specified~~
~~215. NFGS-16202 Power Generating Plants, Diesel Electric (October 1981) (Design 1) 500 to 2500 kW Continuous Duty Units~~
~~Field Tests NDE Tests~~
~~• hydrostatic test of piping None specified • operational tests and acceptance tests~~
~~216. NFGS-16203 Power Generating Plants, Diesel Electric (October 1981) (Design 2) 2,501 kW and Larger Continuous Duty Units~~
~~Field Tests NDE Tests~~
~~• hydrostatic test of piping None specified • electrical Insulation resistance tests • operational and acceptance tests~~
~~A-40 Table A. (Continued)~~
~~Guide Spec, No & Date Guide Spec. Title~~
~~217. NFGS-16204 Power Generating Plants, Diesel Electric (November 1981) (Design 3) 300 to 1,000 kW Standby Duty Units~~
~~Field Tests NDE Tests~~
~~• hydrostatic test of piping None specified • electrical Insulation resistance tests • operational and acceptance tests~~
~~218. NFGS-16205 Power Generating Plants, Diesel Electric (September 1981) (Design 4) 1,001 kW and Larger Standby Duty Units~~
~~Field Tests NDE Tests~~
~~• hydrostatic test of piping None specified • electrical Insulation resistance tests • operational and acceptance tests~~
~~219. NFGS-16207 Power Generating Plants, Diesel Electric (November 1981) (Design 6) 1,001 kW and Larger Emergency Duty Units~~
~~Field Tests NDE Tests~~
~~• hydrostatic test of piping None specified • electrical Insulation resistance tests • operational and acceptance tests~~
~~220. NFGS-16208 Diesel Engine-Generator Set (July 1982) (25-250 kW~~
~~Field Tests NDE Tests~~
~~• operational test None specified~~
~~221. TS-16262 Automatic Transfer Switches (November 1982)~~
~~No field tests specified~~
~~A-41 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~222. NFGS-16301 Underground Electrical Work (April 1984)~~
~~Field Tests NDE Tests~~
~~• test 600 volt conductors for None specified short circuits or accidental grounds • test high voltage cables • test ground rods for ground resistance value~~
~~223. NFGS-16302 Overhead Electrical Work (February 1984)~~
~~Field Tests NDE Tests~~
~~• test ground rods for ground None specified resistance value • operational test • test transformer secondary voltages~~
~~224. NFGS-16304 Pier, Electrical Distribution Amendment -1 for Naval Stations (July 1982)~~
~~No field tests specified~~
~~225. NFGS-16335 Transformers, Substations and (September 1981) Swltchgear, Exterior~~
~~Field Tests NDE Tests~~
~~• acceptance tests None specified • test transformer secondary voltages • dielectric tests (low voltage swltchgear)~~
~~226. NFGS-16402 Ulterior Wiring Systems (February 1983)~~
~~Field Tests NDE Tests~~
~~• operational and acceptance tests None specified • test 600-volt wiring (no short circuits or accldential grounds) • grounding system test~~
~~A-42 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~227. TS-16475 Interior Transformers (August 1979)~~
~~Field Tests NDE Tests~~
~~• operational and acceptance tests None specified • ground resistance tests~~
~~228. NFGS-16462 Pad Mounted Transformers (July 1981)~~
~~Field Tests NDE Tests~~
~~• operational and acceptance tests None specified • ground resistance of ground rods~~
~~229. NPGS-16465 Interior Substations (March 1983)~~
~~Field Tests NDE Tests~~
~~• operational and acceptance tests None specified • relay testing • transformer tests • field dielectric tests • ground resistance tests~~
~~230. TS-16475 Interior Switchgear (August 1979)~~
~~Field Tests NDE Tests~~
~~• operational and acceptance tests None specified • ground resistance tests~~
~~231. NFGS-16492 Motor-Generator Sets, 400 Hertz (January 1983)~~
~~Field Tests NDE Tests~~
~~• operational and acceptance tests None specified • voltage and frequency transiet tests • ground resistance tests~~
~~A-43 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~232. NPGS-16530 Exterior Lighting (March 1985)~~
~~Field Tests NDE Tests~~
~~• operational tests None specified • insulation resistance test • ground resistance tests~~
~~233. NFGS-16560 Airfield Ughting (June 1982)~~
~~Pield Tests NDE Tests~~
• operational tests None specified • electromagnetic interference • test 600-volt class conductors (no short circuits or accidental grounds) • counterpoise and ground rod tests • progress testing for series airfield lighting circuits • electrical acceptance tests for series and multiple airfield lighting circuits • low voltage continuity, ground, and insulation resistance tests • high voltage insulation resistance test • electric tests
~~234. TS-16641 Cathodic Protection by Galvanic (March 1979) Anodes~~
~~field Tests NDE Test~~
~~• static pull test of anode with None specified lead wires • operational test~~
~~A-44 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec, Title~~
~~235. TS-16642 Cathodlc Protection by Impressed (March 1979) Current~~
~~Field Tests NDE Tests~~
~~• static pull test of anode with None specified lead wires • wire for power service (free from short circuits and grounds) • operational test~~
~~236. NFGS-16650 Radio Frequency Interference (June 1983) Power Line Filters~~
~~field Tests NDE Tests~~
~~• operational and acceptance tests None specified~~
~~237. NPGS-16721 Exterior Fire Alarm System (December 1972)~~
~~Field Tests NDE Tests~~
~~• ground resistance None specified • dielectric strength and Insulation resistance~~
~~• operational tests ( power supply, alarm, box and transmitter, signal transmission and recording, trouble line operation, manual-set transmitter test)~~
~~238. TS-16722 Fire Alarm and Fire Detecting (October 1978) System (Local)~~
~~Field Tests NDE Tests~~
~~• operational and functional tests None specified • ground resistance • dielectric strength and insulation resistance~~
~~A-45 Table A. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title~~
~~239. NFGS-16723 Fire Alarm System Radio Type (October 1981)~~
~~Field Tests NDE Tests~~
~~• acceptance test None specified • ground resistance~~
~~A-46 APPENDIX B. REVIEWED NAVY GUIDE SPECIFICATIONS HAVING NDE TESTS~~
~~The Navy Guide Specifications that contain required NDE tests are listed in~~
~~Table B along with the corresponding NDE tests. Of the 239 Guide Specifications~~
~~reviewed (see Appendix A), 29 contained required NDE tests. Some of the tests~~
~~included under NDE tests in Table B were listed as field tests in the~~
~~specifications. Those tests listed as field tests in the specifications are~~
~~denoted with a footnote.~~
~~B-1 Table B. Reviewed Navy Guide Specifications that Contain Required NDE Tests~~
~~Guide Spec. No & Date Guide Spec. Title NDE Tests~~
~~NFGS-02452 Railroad Trackwork • Ultrasonic inspection (September 1984) of welded rail joints~~
~~NFGS-02854 Railroad Track Work • Ultrasonic inspection (March 1983) rail joints (MIL-STD- 1699)~~
~~NFGS-02910 Welding Crane and Railroad • Ultrasonic inspection of (November 1982) Rail - Thermite Method each welded joint~~
~~• Hardness of the weld (6 in. on each side of the joint)~~
~~NFGS-05120 Structural Steel • Nondestructive evaluation (August 1981) (some papers were of welds missing from this spec.)~~
~~NFGS-07110 Membrane Waterproofing *• Watertightness (ponded (April 1983) water for 24 hours)~~
~~TS-0711 Elastomeric Waterproofing *• Watertightness (ponded (September 1980) Sheet Applied water for 24 hours)~~
~~TS-07120 Elastomeric Waterproofing *• Prior to waterproofing (June 1980) System, Fluid Applied application, check moisture content of substrate using a moisture meter~~
*• Watertightness (ponded water for 24 hours)
~~NFGS-07511 Aggregate Surfaced *• Watertightness (ponded (June 1981) Bituminous Built-Up water for 24 hours) Roofing~~
~~NFGS-07512 Smooth Surfaced Watertightness (ponded (July 1981) Bituminous Built-Up water for 24 hours) Roofing~~
~~NFGS-09666 Institutional Sheet Moisture test for (February 1982) Vinyl Flooring concrete subfloor~~
* Listed as field tests in specifications.
~~B-2 Table B. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title NDE Tests~~
~~NFGS-09785 Metallic Type Conductive * Ground resistance (April 1984) and Spark Resistant Concrete of studs, rods, and Floor Finish interconnecting ground wire~~
~~Conductivity of finished floor surface~~
*• Spark resistance of finished floor surface
~~TS-09805.1 Coating Systems (Coal-Tar) * Thickness of coatings (September 1979) for Sheet Piling and Other Steel Waterfront Structures Holidays, pin holes and other defects/ electrical flaw detector~~
TS-09805.2 Coating Systems (Vinyl and *• Thickness of coating (May 1980) Epoxy) for Sheet-Steel Piling and Other Steel Waterfront Holidays, pin holes Structures and other defects/ electrical flaw detector
~~NFGS-09815 High-Build Glaze Coatings Dry film thickness/ (April 1981) Tooke Gage~~
~~NFGS-09809 Protection of Buried Steel * Visual inspection of (September 1981) Piping and Steel Bulkhead protective systems for Tie Rods holes, voids, cracks, and damage~~
~~Test with an electrical flaw detector~~
~~NFGS-09951 Vinyl-Coated Wall Covering Test walls for moisture (August 1982) content/eletric moisture meter~~
~~NPGS-10270 Access Flooring Floor system electrical (July 1983) resistance~~
* Listed as field tests in specification.
~~B-3 ,~~
~~Table B. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title NDE Tests~~
~~TS-11162 Fixed Type Industrial *• Visual inspection of (November 1980) Dockboard dockboard and welds~~
*• Proof-load dockboard
~~• Welds, dye penetrant examined~~
~~• Welds, magnetic patricle tested~~
~~TS-11171 Incinerators , Packaged • Pneumatical test of (October 1978) Controlled-Air Type gas piping systems; soap bubbles to verify tightness of system~~
*• Hydrostatic pressure of oil piping systems (using oil)
~~TS-11301 Packaged, Gravity Oil/ • Hydrostatic test of (April 1980) Water Separator piping~~
~~NFGS- 13661 Fiberglass Reinforced • Holiday detector test (August 1981) Plastic Lining System for of lining Bottoms of Steel Tanks (for Petroleum Fuel Storage)~~
~~TS-13765 Radio Frequency Shielded Seam leak detector~~
~~(April 1979) Enclosures , Demountable testing (shielding), TZ£e "sniffer"~~
~~TS-13766 Radio Frequency Shielded Seam leak detector (April 1979) Enclosures, Welded Type testing of welds, "sniffer"~~
~~NFGS-1A304 Portal Crane Track Ultrasonic inspection (January 1984) Installation of welded rail joints~~
* Listed as field test in specification.
~~B-4 ,~~
~~Table B. (Continued)~~
~~Guide Spec. No & Date Guide Spec. Title NDE Tests~~
NFGS-15116 Welding Pressure Piping *• Visual inspection of (July 1982) welds • NDE personnel shall be certified as qualified- radiographic, liquid penetrant, magnetic particle, ultrasonic- examination of welds conform to "ASME Boiler and Pressure Vessel Code, Section V."
~~NFGS-15403 Nonflammable Medical *• Leak tests of (March 1981) Gas Systems systems~~
~~NFGS-15411 Compressed Air Systems *• Visual inspection~~
~~(July 1983) (Non-Breathing Air Type ) of welds • NDE personnel shall be certif ied-radiographic liquid penetrant, magnetic particle-for welds~~
~~NFGS-15612 Gas Distribution System *• Visual inspection of (April 1984) welds • Electrical holiday detector for discontinuities in pipe coatings~~
~~NFGS-15653 Unitary Air Conditioning • Leak testing (electronic (June 1984) Systems type leak detector)~~
* Listed as field test in specification
~~B-5~~
~~APPENDIX C. LISTS OF REVIEWED NCEL TECHDATA SHEETS AND NCEL TECHNICAL AND RESEARCH REPORTS THAT CONTAIN NDE METHODS~~
The Navy publications provided by NCEL and NAVFAC which were reviewed are listed in this appendix. Section 2.4 provides information about these types of reports. Table Cl contains a list of reviewed NCEL Techdata Sheets and
~~Table C2 contains a list of reviewed NCEL technical and research reports.~~
~~C-1 Table CI. List of Reviewed NCEL Techdata Sheets that Contain NDE Methods~~
~~NCEL Techdata Sheet 79-09, "Inspection of Painting," Port Hueneme , CA, September 1979.~~
~~NCEL Techdata 75-31, "Measuring Water Permeability of Masonry Walls," Port Hueneme, CA, December 1985.~~
~~NCEL Techdata Sheet 82-13, "Leak Detection in Pipelines," Port Hueneme, CA, September 1982.~~
~~NCEL Techdata Sheet 84-05, "Infrared Thermometers for Roofing Inspectors," Port Hueneme, Ca, March 1984.~~
~~NCEL Techdata Sheet 77-20, "Use of Windsor Probe Test System for Strength Evaluation of Concrete in Naval Construction," Port Hueneme, CA, December 1977~~
~~NCEL Techdata Sheet 80-12, "Problems with Underwater Ultrasonic Inspection," Port Hueneme, CA, October 1980.~~
~~NCEl Techdata Sheet 76-13, Inspection Methods for Wood Fender and Bearing Piles," Port Hueneme, CA, September 1976.~~
~~NCEL Techdata Sheet 82-14, "Locating and Tracing Buried Metallic Pipelines," Port Hueneme, CA, September 1982.~~
~~C-2 Table C2 . List of Reviewed NCEL Technical and Research Reports that Contain NDE Methods~~
~~NCEL Technical Memorandum M-43-81-07, "An Evaluation of Pulse Echo Ultrasonic Techniques for Underwater Inspection of Steel Waterfront Structures,"~~
~~R. L. Bracket t and L. W. Tucker, Port Hueneme , CA, May 1981.~~
~~NCEL Technical Memorandum M-43-81-08, "Ultrasonic Inspection of Wooden Waterfront Structures," C. A. Keeney, Port Hueneme, CA, May 1981.~~
~~NCEL Technical Memorandum M-51-81-11, "Concepts for Detecting Weak Spots in Pavement-Encased Trackage on Waterfront Facilities," G. E. Warren, Port Hueneme, CA, August 1981.~~
~~NCEL Technical Note N-1594, "Nondestructive Test Equipment for Wire Rope," H. H. Haynes and L. D. Underbakke, Port Hueneme, CA, October 1980.~~
~~NCEL Technical Memorandum M-52-80-10, "Specialized Roof Moisture Inspection," Robert L. Alumbaugh and John R. Keeton, Port Hueneme, CA, September 1980.~~
~~NCEL Technical Memorandum M-52-81-06, "Inspection of POL Supply Facilities," Thorndyke Roe, Jr., Port Hueneme, CA, September 1981.~~
~~NCEL Technical Memorandum M-55-81-04, "Inspection of Underground Utility Lines-Milestone Zero Report," S. S. Wang, Port Hueneme, CA, July 1981,~~
~~NCEL Technical Memorandum M-55-81-06, "Inspection of Underground Utility Lines," S. S. Wang and S. J. Oppedisano, Port Hueneme, CA, November 1981,~~
~~NCEL Technical Memorandum M-43-78-09, "Underwater Inspection and Nondestructive Testing of Waterfront Structures: A State of the Art Assessment," R. L. Brackett, Port Hueneme, CA, June 1978.~~
~~NCEL Technical Memorandum M-51-80-27, "Noncontact Displacement Measurement as an Inspection Tool for Naval Shipyard Trackage," G. E. Warren, Port Hueneme, CA, December 1980.~~
~~NCEL Technical Memorandum M-52-77-3, "Roofing Survey of Naval Shore Bases," J, R. Keeton and R. L, Alumbaugh, Port Hueneme, CA, March 1977.~~
NCEL Technical Note N-1624, "Underwater Inspection of Waterfront Facilities: Inspection Requirements Analysis and Nondestructive Testing Technique Assessment," R. L. Brackett, W. J. Nordell, and R. D, Rail, Port Hueneme, CA, March 1982.
~~NCEL Technical Note N-1632, "Evaluation of NDT Equipment for Specialized Inspection," G. Warren, Port Hueneme, CA, June 1982.~~
~~NCEL Technical Report R-903, "Pulse Echo Ultrasonic Techniques for Underwater Inspection of Steel Waterfront Structure," R. L. Brackett, L. W. Tucker, and R. Erich, Port Hueneme, CA, June 1983.~~
~~C-3 Table C2. (Continued)~~
~~NCEL Technical Note N-1233, "Calibration of Windsor Probe Test System for Evaluation of Concrete in Naval Structures," J, R. Keeton and V. Hernandez, Port Hueneme, CA, June 1972.~~
~~NCEL Technical Note N-1703, "Evaluation of Nondestructive Underwater Timber Inspection Techniques," C. A. Keeney and S. E. Pollio, Port Hueneme, CA, August 1984.~~
~~NCEL Technical Memorandum M-43-84-01, "Evaluation and Comparison of Commerical Ultransonic and Visual Inspections of Timber Piles," A. P. Smith, Port Hueneme, CA, December 1983.~~
Technical Memorandum M-53-85-03, "Detection of Underground Utilities and Obstacles with Ground Penetration Radars - An Initiation Decision Report," M. C. Hironaka and G. D. Cline, Port Hueneme, CA, January 1985.
~~Technical Memorandum M-53-82-02, "Dectection of Underground Utilities and Obstacles - An Initiation Decision Report," M. C. Hironaka, Port Hueneme,~~
~~CA, September 1982 .~~
~~Technical Memorandum M-53-84-5, "Ground Probing Radars and Hand-Held Detectors for Locating Underground Utility Lines and Other Objects," M. C. Hironaka and G. D. Cline, Port Hueneme, Ca, August 1984.~~
NCEL Technical Memorandum M-43-81-07, "An Evaluation of Pulse Echo Ultrasonic Techniques for Underwater Inspection of Steel Waterfront Structures," R. L. Bracket t and L. W. Tucker, Port Hueneme, CA, May 1981.
NCEL Technical Memorandum M-43-78-09 , "Underwater Inspection and Nondestructive Testing of Waterfront Structures: A State-of-the-Art Assessment Report," R. L. Brackett, Port Hueneme, CA, February 1984.
~~NCEL Technical Memorandum tm no: 52-84-04, "Design and Development of a Portable Infrared Spectrophotometer for NDT Analysis of Coatings," T. Novinson, Port Hueneme, CA, November 1983.~~
NCEL Technical Memorandum tm no: 52-83-03, "Laboratory Prototype of a Portable Infrared Spectrophotometer for NDT Field Analysis of Coatings and Other Organic Materials," T. Novinson and D. S. Kyser, Port Hueneme, CA, November 1982.
~~NCEL Technical Note N-1179, "Measuring Water Permeability of Masonry Walls," H. Hochmam, Port Hueneme, CA, August 1971.~~
~~NCEL Technical Memorandum M-55-82-01 , "Leak Detection in Underground Utility Lines-Status Report," S. S. Wang and S. J. Oppendisano, Port Hueneme, CA, May 1982.~~
~~C-4 APPENDIX D. ASTM STANDARDS FOR NDE METHODS FOR CONSTRUCTION MATERIALS AND BUILDING COMPONENTS~~
ASTM has recognized the need for standards covering nondestructive evaluation methods for a variety of materials and applications. Consequently, a number of ASTM standards for NDE procedures have been issued. ASTM standards for
NDE methods for concrete are listed in Table Dl . Some ASTM standards for other common NDE methods are listed in Table D2. As new ASTM standards for NDE appear, they can be located by reviewing the index to ASTM standards which is published annually.
~~D-1 Table Dl . ASTM Standards for NDE Methods for Concrete~~
~~NDE Method ASTM Standard and Designation~~
~~Rebound Hammer Test for rebound number of hardened concrete: C 805~~
~~Penetration Probe Test for penetration resistance of~~
~~hardened concrete : C 803~~
~~Ultrasonic Pulse Velocity Test for pulse velocity through concrete: C 597~~
~~Nuclear Moisture Meter Test for moisture content of soil and soil-aggregate in place by nuclear methods (shallow depth): D 3017~~
~~Cast-in-place Pullout Test for pullout strength of hardened concrete: C 900~~
~~Visual Practice for examination of hardened concrete in constructions: C 823~~
~~Corrosion of Rebars Test for half cell potentials of reinforcing steel in concrete: C 876~~
~~Mechanical Properties Test for fundamental transverse, longitudinal, and torsional frequencies of concrete specimens: C 215 (laboratory method)~~
~~D-2 Table D2 . ASTM Standards for NDE Methods for Construction Materials and Building Components~~
~~NDE Method ASTM Standard and Designation~~
~~Acoustic Emission Practice for acoustic emission monitoring during continuous welding: E 749~~
~~Practice for acoustic emission monitoring of structures during controlled stimulation: E 569~~
~~Practice for acoustic emission examination of reinforced thermosetting resin pipe: E 1118~~
~~Air Leakage Method for Determining Air Leakage Rate by Tracer Dilution: E 741~~
~~Method for Determining Air Leakage Rate by Fan Pressurizatlon: E 779~~
~~Coating Thickness Testing Practice for measuring coating thickness by magnetic-field or eddy-current (electromagnetic) test methods: E 376~~
~~Measurement of thickness of anodic coatings on aluminum and of other nonconductive coatings on non-magnetic basis metals with eddy-current instruments: B 244~~
~~Measurement of dry film thickness of nonmagnetic coatings applied to a ferrous base: D 1186~~
~~Measurement of dry film thickness of nonconductive coatings applied to a nonferrous metal base: D 1400~~
~~Measurement of film thickness of pipeline coatings on steel: G 12~~
~~Measurement of dry film thickness of protective coating systems by destructive means: D 4138 (Tooke gage)~~
~~Practice for measurement of wet film thickness by notch gages: D 4414~~
~~Measurement of wet film thickness of organic coatings: D 1212~~
~~D-3 Table D2 (Continued)~~
~~NDE Method ASTM Standard and Description~~
~~Eddy Current Method Test for electrical conductivity by~~
~~use of eddy current : B 342~~
~~Practice for In situ electromagnetic (eddy-current) examination of nonmagnetic heat exchanger tubes: E 690~~
~~Practice for electromagnetic (eddy-current) testing of seamless copper and copper alloy tubes: E 243~~
~~Hardness Testing Hardness conversion tables for metals (relationship between Brlnell hardness, Vlckers hardness, Rockwell hardness, Rockwell superficial hardness, and~~
~~Knoop hardness) : E 140~~
~~Test for Brlnell hardness of metallic materials: E 10~~
~~Test for Vlckers hardness of metallic materials: E 92~~
~~Test for Indentation hardness of metallic materials by portable hardness testers: E 110~~
~~Rapid indentation hardness testing of metallic materials: E 103~~
~~Test for Rockwell hardness and Rockwell superficial hardness of metallic materials: E 18~~
~~Test for film hardness by pencil test: D 3363~~
~~Magnetic Particle Practice for magnetic particle examination: E 709~~
~~Specification for magnetic particle Inspection of large crankshaft~~
~~f orglngs : A 456~~
~~D-4 Table D2 (Continued)~~
~~NDE Method ASTM Standard and Description~~
~~Magnetic Particle Reference photographs for magnetic (Continued) particle indications on castings: E 125~~
~~Method for magnetic particle examination~~
~~of steel f orgings : A 275~~
~~Terminology of symbols and definitions relating to magnetic testing: A 340~~
~~Penetrant Testing Practice for liquid penetrant inspection method: E 165~~
~~Reference photographs for liquid penetrant inspection: 433~~
~~Radiographic Testing Reference radiographs for steel coatings up to 2 in. (51 mm) in thickness: E 446~~
~~Reference radiographs for heavy-walled (2 to 4-1/2 inch) steel castings: E 186~~
~~Reference radiographs for steel fusion welds: E 390~~
~~Method for controlling quality of radiographic testing: E 142~~
~~Practice for radiographic testing: E 94~~
~~Soils Inspection Method for density of soil in place by the sand-cone method: D 1556~~
~~Methods for density of soil and soil- aggregate in place by nuclear methods (shallow depth): D 2922~~
~~Methods for moisture-density relations of soils and soil-aggregate mixtures, using 5.5-lb (2.49 kg) rammer and 12-in. (305 mm) drop: D 698~~
~~Method for penetration test and split-barrel sampling of soils: D 1586~~
~~D-5 Table D2 (Continued)~~
~~NDE Method ASTM Standard and Description~~
~~Soil Inspection Classification of soils for engineering (Continued) purposes: D 2487~~
~~Method for deep, quasi-static cone and friction-cone penetration tests of soil: D 3441~~
~~Ultrasonic Testing Practice for measuring thickness by manual ultrasonic pulse-echo contact method: E 797~~
~~Practice for ultrasonic pulse-echo straight-beam testing by the contact method: E 114~~
~~Practice for ultrasonic contact~~
~~examination of weldments : E 164~~
~~Practice for ultrasonic examination of~~
~~heavy steel f orgings : A 388~~
~~Straight-beam ultrasonic examination of steel plates: A 435~~
~~Practice for ultrasonic inspection of metal pipe and tubing: E 213~~
~~Practice for measuring ultrasonic velocity in materials: E 494~~
~~Testing for leaks using ultrasonics: E 1002~~
~~Practice for ultrasonic examination of longitudinal welded pipe and tubing: E 273~~
~~Uplift Testing Field testing uplift resistance of roofing systems employing steel deck rigid insulation and bituminous built-up roofing; E 907~~
~~Window Testing Method for strucutural performance of glass in windows, curtain walls, and doors under the influence of uniform static loads by nondestructive method: E 998~~
~~D-6 FORM NBS-1 MA (REV, n -84)~~
~~U.S. DEPT. OF COMM. I. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication Date REPORT NO. DATA BIBLIOGRAPHIC NBS/TN-1247 June 1987 SHEET (See /n struct/on s)~~
~~4. TITLE AND SUBTITLE~~
~~Review of Nondestructive Evaluation Methods Applicable to Construction Materials and Structures~~
~~5. AUTHOR(S) Robert G. Mathey and James R. Clifton~~
~~6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions) 7. Contract/Grant No.~~
~~NATIONAL BUREAU OF STANDARDS U.S. DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered GAITHERSBURG, MD 20899 Final~~
~~9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP) Naval Civil Engineering Laboratory Port Hueneme, CA 93043-5003~~
~~10. SUPPLEMENTARY NOTES~~
~~[^21 Document describes a computer program; SF-185, FlPS Software Summary, is attached.~~
11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a si gnificant bibliography or literature survey, mention it here) Nondestructive evaluation (NDE) methods for evaluating in situ construction materials and for condition assessment of building components and systems were identified and are described. This report is intended to help inspectors and those involved in condition assessment choose appropriate NDE methods for specific building materials, components, and systems. Important properties of building materials along with important performance requirements for building components are listed, and appropriate NDE methods lot determining these properties are recommended. In many cases the advantages and limitations of the NDE methods are presented. Potential NDE methods which may or may not require further research and development before they are ready for routine use were also identified and are briefly described. In addition, ASTM standards for NDE methods for concrete and other building materials and components were identified. In a related aspect of the study, current Navy practices relative to the use of NDE methods in the construction and service cycle of buildings and other structures were reviewed. This review was based on Navy reports and documents provided by NCEL and NAVFAC, and on discussions with NAVFAC personnel involved with buildings and structures problems where NDE methods are used for diagnostic purposes. Navy Guide Specifications were examined for required tests, both NDE and destructive, of in situ building materials and components
12. KEY WORDS (S/x to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons) building components; building diagnostics; building materials; condition assessment; construction materials; in situ evaluation; nondestructive evaluation
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