'— Z? A DATA BASE FOR AGING OF STRUCTURAL MATERIALS* C. B. Oland and D. J. Naus Oak Ridge National Laboratory, Oak Ridge, TN USA S. JERATH University of North Dakota, Grand Forks, ND USA ABSTRACT The U.S. Nuclear Regulatory Commission (USNRC) initiated a Structural Aging (SAG) Program at the Oak Ridge National Laboratory (ORNL). The objective of the program is to provide assistance in identifying potential structural safety issues and to establish acceptance criteria for use in nuclear power plant evaluations for continued service. One of the main pans of the program focuses on the development of a Structural Materials Information Center where long-term and environment-dependent material properties are being collected and assembled into a data base. This data base is presented in two complementary formats. The Structural Materials Handbook is an expandable, hard-copy reference document that contains the complete data base for each material. The Structural Materials Electronic Data Base is accessible using an IBM compatible personal computer. This paper presents an overview of the Structural Materials Information Center and briefly describes the features of the handbook and the electronic data base. In addition, a proposed method for using the data base to establish current property values for materials in existing concrete structures and to es- timate the future performance of these materials is also presented. INTRODUCTION Material properties, data, and information for structural materials typically used to construct rein- forced concrete structures in nuclear power plants are being collected and assembled into a data base at the Structural Materials Information Center. Descriptive information, compositional char- acteristics, baseline data, reference values, and processing parameters for each material are in- cluded along with at least one time-dependent or environment-dependent material property. The need for this type of data base was established in a report on concrete component aging and its significance relative to the life extension of nuclear power plants f 1}. A review of materials prop- em' data bases [2] revealed that no data bases existed that met the needs of the SAG Program. Material properties, data, and information collected at the Structural Materials Information Center are presented in two complementary formats. The Structural Materials Handbook is an expand- *Research sponsored by the Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission under Interagcncy Agreement 1886-8011-9B wiih ihe U.S. Department of Energy under Contract DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc. The submiucd manuscript has been authored by a contractor of the U. S. Government under Contract DE-AC05- 840R21400. Accordingly, the U. S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U. S. Government purposes. O1STRTBUT1ON OF THIS DOCUfvYl=flT IS UNLIMITED DISCLAIMER This report was prepared us un account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trudc nume, trademark, manufacturer, or otherwise docs not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. able, hard-copy reference document that contains complete sets of data and information for each material in the data base and serves as the information source for the Structural Materials Electronic Data Base. The electronic version provides access to the data using a data base man- agement software system that operates on an IBM-compatible personal computer. Reports de- scribing the development of the Structural Materials Information Center [3] and the formats being used to report data and information in the handbook |4] have been prepared. Examples of how the material properties in the data base could potentially be used to assist in performing current or continued service assessments of reinforced concrete structures in nuclear power plants [5] have also been developed. The data base currently includes properties for the materials listed in Table 1. The data and information included in the handbook and the electronic data base are presented using the International System (SI) of Units and customary units. Table 1. Types of materials available from the Structural Materials Information Center. Presentation Format Material Structural Materials Handbook Structural Materials Type Volumes 1, 2, and 3 Electronic Data Base File Name Portland Cement Chapter CONCRETE.DB Concrete 01 Metallic Chapter REBAR.DB Reinforcement 02 Prestressing Chapter TENDON.DB Tendon 03 Structural Chapter STEEL.DB Steel 04 Rubber Chapter RUBBER.DB 05 STRUCTURAL MATERIALS HANDBOOK The Structural Materials Handbook consists of four volumes that are published in loose-leaf binders. Volume 1 contains design and analysis information useful for structural assessments and structural margins evaluations. This volume contains performance curves for mechanical, ther- mal, physical, and other properties presented as tables, graphs, and mathematical equations. Volume 2 reflects the supporting documentation and includes test results and data used to develop the performance curves presented in Volume 1. Material data sheets are provided in Volume 3. These sheets include general information, baseline data, and reference values as well as material composition and constituent material properties. Volume 4 contains appendices that describe the handbook organization, updating and revision control procedures, and electronic data base access- ing information. Each chapter in Volumes 1, 2, and 3 is organized to include the materials prop- erty data base for a particular type or category of material. As shown in Table 1, Chapter 1 ad- dresses portland cement concretes; Chapter 2, metallic reinforcements; Chapter 3, prestressing tendons; Chapter 4, structural steels; and Chapter 5, rubbers. Each material in the data base is assigned a unique seven-character material code which is used in the handbook and the electronic data base to organize materials with common characteristics. This code consists of a chapter index, a group index, a class index, and an identifier. The chapter in- dex is used to represent the various material systems in the data base. The group index is used to arrange materials in each chapter into suDsets of materials having distinguishing qualities such as 3 common compositional traits. The class index is used to organize groups of materials with com- mon compositional traits into subsets having a similar compositional makeup or chemistry. The identifier is used to differentiate structural materials having the same chapter, group, and class in- dices according to a specific concrete mix, ASTM standard specification for metallic reinforce- ment, etc. A wide variety of descriptive information and materials property data are contained in the data base as tables, notes, and graphs. In order to organize the data base, each entry is assigned a unique four-digit property code selected from an established set of material property categories. The property code ranges and corresponding material property categories are used consistently in the handbook and the electronic data base. Volumes 1 and 2 are formatted so that the performance curves and supporting documentation reported on each page correspond to the property code that appears in the page heading. Volume 3 is formatted so that the information and data presented on each material data sheet correspond to a particular property code range (e.g., 1000-1999, 2000- 2999, etc.). Since each material data sheet can include combinations of general information, constituent material, plastic concrete, mechanical, thermal, physical, and other properties, these pages are formatted to contain information and data that pertain to only one particular property code range. Each reference document that is used as an information source at the Structural Materials Information Center is assigned a unique integer identifier. This number and the reference source that it represents are used synonymously in the data base. Since each reference is used in Volumes 1, 2. and 3 and may be used for more than one property or structural material, a com- plete list of all references used in the handbook appears in Appendix E of Volume 4. STRUCTURAL MATERIALS ELECTRONIC DATA BASE The Structural Materials Electronic Data Base operates on an IBM-compatible personal computer using a commercially-available data base management system (6]. This system of hardware and software provides access to material properties data and information contained on electronic data base files. The electronic data base management system includes two software programs: Mat.DB [7] and EnPlot [8]. These programs are available from ASM INTERNATIONAL, Materials Park, Ohio. Each software package includes a user's manual