DOCSLIB.ORG

Assessment of Existing Concrete Bridges Bending Stiffness As a Performance Indicator

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Assessment of Existing Concrete Bridges Bending Stiffness As a Performance Indicator ISSN: 1402-1544 ISBN 978-91-86233-XX-X Se i listan och fyll i siffror där kryssen är DOCTORAL T H E SIS Markus Bergström Department of Civil, Mining and Environmental Engineering Division of Structural Engineering Assessment of Existing ISSN: 1402-1544 ISBN 978-91-86233-11-2 Concrete Bridges Luleå University of Technology 2009 Assessment Bending Stiffness as a Performance Indicator of Existing Concrete Bridges Bending stiffness stiffness Bending Bending Stiffness as a Performance Indicator I II III IV Load/Time Markus Bergström Luleå University of Technology Doctoral Thesis Assessment of Existing Concrete Bridges Bending Stiffness as a Performance Indicator Markus Bergström Division of Structural Engineering Department of Civil, Mining and Environmental Engineering Luleå University of Technology SE-971 87 Luleå Sweden http://www.ltu.se/ Sweet are the memories sweet is the goal, heading for new challenges to inspire the soul Assessment of Existing Concrete Bridges – Bending Stiffness as a Performance Indicator MARKUS BERGSTRÖM Avdelningen för byggkonstruktion Institutionen för samhällsbyggnad Luleå tekniska universitet Akademisk avhandling som med vederbörligt tillstånd av Tekniska fakultetsnämnden vid Luleå tekniska universitet för avläggande av teknologie doktorsexamen, kommer att offentligt försvaras i universitetssal F1031, fredagen den 6 mars 2009, kl. 10.00. Fakultetsopponent: Professor Paulo Cruz, University of Minho, Portugal Betygsnämnd: Professor Björn Engström, Chalmers tekniska högskola, Sverige Professor Sven Thelandersson, Lunds tekniska högskola, Sverige Professor Uday Kumar, Luleå tekniska universitet, Sverige Universitetstryckeriet, Luleå ISBN 978-91-86233-11-2 ISSN 1402-1544 Luleå 2009 WWW.LTU.SE Front page: The illustration shows a reinforced concrete (RC) member which passes through four phases; Un-cracked (I), Crack forming (II), Crack stabilised (III) and Failure (IV). The propagation is governed by increased loads or degradation. Both of these could be time dependent during certain conditions, which imply that the stiffness of an RC members in time could also develop in this manner. The present research has focused on the bending stiffness used as a performance indicator, and how it can be used from a bridge management perspective. Preface The present doctoral thesis reflects my work between July 2004 and March 2009 at the Division of Structural Engineering at Luleå University of Technology (LTU). Without funding from “the Swedish Construction Industry’s Organisation for Research and Development (SBUF)”, and “the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS)” this would not have been possible. A sincere thanks is addressed to these organisations for the interest in my research. The scholarships from Elsa and Sven Thysell’s Foundation, J Gust Richerts Memorial Fund and the Wallenberg Foundation have made it possible to represent LTU and the present research at international conferences, and are of course also greatly acknowledged. All the staff at the Department of Civil, Mining and Environmental Engineering, especially the staff at the Division of Structural Engineering, are apprechiated for the discussions in the coffee room. I can only remember good things about working close to my colleagues and friends within the research group “Innovative Materials and Structures”. I would like to thank my PhD-student companions for valuable times signed both work and leisure, and ofcourse my supervisor Prof. Björn Täljsten and assistant supervisor Dr. Anders Carolin for supporting me during these years. It has been valuable and pleasant to have you as supervisors, and not only at work. I hope we can keep in contact in the future. I would also like to thank the staff at Testlab for all their help with my tests and measurements. Special attention should be given to Tech. Dr. Claes Fahleson, Civ. Eng. Georg Danielsson and Mr. Lars Åström for excellent cooperation. All my colleagues at Norut Narvik AS, located in Narvik (Norway), are appreciated both for valuable collaboration and kind hospitality during my visits. Prof. Lennart Elfgren and Tech. Dr. Martin Nilsson should be acknowledged for giving valuable comments during the final work with the thesis, and also Prof. Mats Emborg for leading the division during this time. Special thanks go to my family, friends and especially to my fiancé Sofi, who all bring joy into my life. Markus Bergström March 2009 I Summary Optimizing the use of existing civil reinforced concrete (RC) structures could be interpreted in such a way as to say that the capacity should be used and taken care of in an effective manner, both from a technical and economical point of view, keeping the safety in mind. Achieving this requires thorough understanding of the structure and also of the tools used for assessing current and future capacity and needs. Monitoring together with finite element modelling could give relevant and important information about a structure’s capacity. In a case where monitoring alone is used, it is beneficial if a quantity is monitored which is interpretable on material and geometrical level. It is further important that the measure is practically possible to capture, and that it reflects the behaviour in a theoretically well-known mode. One example of a quantity which fulfils these requirements is the bending stiffness. In the Serviceability Limit State (SLS), in particular, a high bending stiffness is beneficial as this reduces deflections, vibration amplitudes and crack widths. It is shown within the thesis that four phases are distinguished during loading of an RC member; Un-cracked phase (I), Crack forming phase (II), Crack stabilised phase (III) and Failure phase (IV). It is also shown that corrosion and flexural strengthening are possible to capture through the bending stiffness by monitoring the curvature. Linear elastic theory has in addition been concluded to give satisfactory results in terms of good agreement between measured and theoretical results. It is shown that it is possible to determine the highest load which the structure has been previously exposed to, presuming that the structural element has not reached phase (III). The stiffness is almost constant in phase (III) which implies that it is the same for a certain load interval. One limitation coupled to the stiffness plateau formed in phase (III) is that it is difficult to predict a possible failure by monitoring the bending stiffness, caused by the limited forewarning prior to the beginning of phase (IV). Other tools, such as reliability-based assessment, become especially important here since active degradation, for example, is difficul to verify by curvature measurements in phase (III). Estimating the safety, and also finding the probable failure mode is important since curvature measurement is not effective in the Ultimate Limit States (ULS) and only captures the behaviour in bending. In the reliability-based assessment, the agreement between analytical results and actual capacity of the particular failure mode must be treated with special attention, since it has been shown that the model uncertainty can affect both the safety level and also probable failure mode. If it can be shown from monitoring that the structure is located within phase (I) the load effect during the past time has not affected the integrity of the structure in terms of bending cracks. III It is preferrable to use the global curvature when evaluating the bending stiffness, since this property gives a more robust average curvature and also additional information about the structural member. Especially changing bond properties, during e.g. corrosion, is more likely to be detected if the global curvature is monitored. Another important conclusion is that the local and global stiffness development is very similar. This implies that a crack at a certain location is not allowed to increase without redistribution of stresses, which affects the global stiffness in an comparable extent. Two criteria are suggested for the least distance over which the global curvature should be measured, LG. The first one concerns the fact that at least four macro cracks is suggested to be covered and is based on the maximum crack spacing recommended by Eurocode (2004). The other requirement is that the distance should not be that small that the estimated deflection become less than one hundred times the in-built measurement error in the displacement gauge. A measurement error above one percent is hence not allowed. Curvature assessment could be useful from three different aspects Condition assessment. The monitored quantity is back-calculated to input data, such as material property or geometry. That is, solving the inverse bridge management problem. Decisions about the use of the structure are then based on the outcome of this assessment. Refined calculations in serviceability and ultimate limit states. Use the results to refine the models used for SLS and ULS performance. For example, it might be possible to treat the structure in its actual condition. Optimized LCC. Time until a major repair and/or strengthening procedure is estimated using the bending stiffness development captured by curvature measurement. The approach using bending stiffness as a performance indicator is applied in two case studies in Sweden, the Panken road bridge located east of Karlstad and the railway bridge located in Örnsköldsvik. The Panken Bridge was located within phase (III) (crack stabilised phase), while the Örnsköldsviks
Load more

Recommended publications
  • Research PUBLICATION NO
    THE NORDIC CONCRETE FEDERATION 1/2014 PUBLICATION N0. 49 Nordic Concrete Research PUBLICATION NO. 49 1/2014 NORDIC CONCRETE RESEARCH EDITED BY THE NORDIC CONCRETE FEDERATION CONCRETE ASSOCIATIONS OF: DENMARK FINLAND ICELAND NORWAY SWEDEN PUBLISHER: NORSK BETONGFORENING POSTBOKS 2312, SOLLI N - 0201 OSLO NORWAY VODSKOV, JUNE 2014 Preface Nordic Concrete Research is since 1982 the leading scientific journal concerning concrete research in the five Nordic countries, e.g., Denmark, Finland, Iceland, Norway and Sweden. The content of Nordic Concrete Research reflects the major trends in the concrete research. Nordic Concrete Research is published by the Nordic Concrete Federation which also organizes the Nordic Concrete Research Symposia that have constituted a continuous series since 1953 in Stockholm. The Symposium circulates between the five countries and takes normally place every third year. The next symposium, no. XXII, will be held Reykjavik, Iceland 13 - 15 August 2014, in parallel with the ECO-CRETE conference. More information on the research symposium can be found on www.rheo.is. More than 110 papers will be presented. Since 1982, 414 papers have been published in the journal. Since 1994 the abstracts and from 1998 both the abstracts and the full papers can be found on the Nordic Concrete Federation’s homepage: www.nordicconcrete.net. The journal thus contributes to dissemination of Nordic concrete research, both within the Nordic countries and internationally. The abstracts and papers can be downloaded for free. The high quality of the papers in NCR are ensured by the group of reviewers presented on the last page. All papers are reviewed by three of these, chosen according to their expert knowledge.
    [Show full text]
  • 1P-251 1 Using Metakaolin to Improve the Compressive Strength and The
    INVACO2: International Seminar, INNOVATION & VALORIZATION IN CIVIL ENGINEERING & CONSTRUCTION MATERIALS N° : 1P-251 F. Pacheco Torgal, University of Minho, Guimarães, Portugal Using metakaolin to improve the compressive strength and the durability of fly ash based concrete F. Pacheco Torgal*, Arman Shasavandi, Said Jalali University of Minho, Research Unit C-TAC, Sustainable Construction Group, Guimarães, Portugal Abstract Partial replacement of Portland cement by pozzolanic and cimentitious by-products or mineral additions that allow for carbon dioxide emission reductions is a major issue in the current climate change context. However, the use of low pozzolanic activity by-products like fly ash can cause a decrease relatively early in compressive strength. In this paper, the effect of metakaolin and fly ash on strength and concrete durability was investigated. The durability was assessed by different means of water absorption, oxygen permeability and concrete resistivity. Results show that partial replacement of cement by 30% fly ash leads to a decrease relevantly early in compressive strength, when compared to a reference mix of 100% Portland cement. Results also show that using 15% fly ash and 15% metakaolin replacement is responsible for minor strength loss but leads to outstanding durability improvement. Keywords: Concrete, cement, fly ash, metakaolin, strength, durability --------------------------------------- * [email protected] 1. INTRODUCTION Although Portland cement demand are decreasing in industrial nations, it is increasing dramatically in developing countries [1,2]. Cement demand projections shows that by the year 2050 it will reach 6000 million tons. Portland cement production leads to major CO 2 emissions, results from calcination of limestone (CaCO 3) and from combustion of fossil fuels, including the fuels required to generate the electricity power plant, accounting for almost 0.7 tons of CO 2 per ton.
    [Show full text]
  • Use of GGBS Concrete Mixes for Aggressive Infrastructural Applications
    UCD School of Architecture, Landscape and Civil Engineering Use of GGBS Concrete Mixes for Aggressive Infrastructural Applications ENTERPRISE IRELAND ECOCEM IRELAND INNOVATION PARTNERSHIP PROGRAMME PROJECT CODE IP/2008/0540 Executive summary The case for research into the deterioration associated with water and wastewater infrastructure has been clearly made. For example in the US alone, the Congressional Budget Office has estimated that annual investments of up to $20 billion and $21 billion is required to provide adequate infrastructure for drinking water and wastewater respectively. It is also estimated that the annual operation and maintenance costs associated with drinking water and wastewater infrastructure to be in excess of $31 billion and $25 billion respectively. In Ireland, the Government have previously announced that under the Water Services Investment Plan, €5.8 billion will be spent on this sector. As such, this represents a potentially lucrative market that exists both in Ireland and internationally. Research was conducted into the performance of concrete samples manufactured using a range of binder combinations which were subjected to aggressive environments selected to represent the most extreme of conditions they will encounter in service. These included attack from sulfates and from biogenic sulfuric acid. The test results found that: • In sodium sulfate expansion tests, traditional CEM I cements performed significantly poorer than all other binder combinations. Samples manufactured using the newer CEM II/A-L binders displayed increased resistance to sulfate attack but still failed to meet standard performance criteria. • The samples with the highest resistance to sulfate attack were those that contained 50% or 70% GGSB as a cement replacement level, which displayed very low expansion levels.
    [Show full text]
  • Alkali-Aggregate Reactions 162 163
    161 Session A7: ALKALI-AGGREGATE REACTIONS 162 163 Alkali release from typical Danish aggregates to potential ASR reactive concrete Hans Chr. Brolin Bent Grelk Thomsen M.Sc, Chief Consultant M.Sc Grelk Consult DTU Civil Engineering [email protected] Brovej, Building 118 DK - 2800 Kgs. Lyngby [email protected] Ricardo Antonio Kurt Kielsgaard Hansen Barbosa Associated professor, Ph.D. Ph.D. DTU Civil Engineering DTU Civil Engineering Brovej, Building 118 Brovej, Building 118 DK - 2800 Kgs. Lyngby DK - 2800 Kgs. Lyngby [email protected] [email protected] ABSTRACT Alkali-silica reaction (ASR) in concrete is a well-known deterioration mechanism affecting the long term durability of Danish concrete structures. Deleterious ASR cracking can be significantly reduced or prevented by limiting the total alkali content of concrete under a certain 3 threshold limit, which in Denmark is recommended to 3 kg/m Na2Oeq.. However, this threshold limit does not account for the possible internal contribution of alkali to the concrete pore solution by release from aggregates or external contributions from varies sources. This study 3 indicates that certain Danish aggregates are capable of releasing more than 0.46 kg/m Na2Oeq. at 13 weeks of exposure in laboratory test which may increase the risk for deleterious cracking due to an increase in alkali content in the concrete. Key words: Alkali-silica reaction, aggregate, alkali content, durability. 1. INTRODUCTION ASR is a complex physical and chemical reaction between water, alkali in the concrete pore solution and reactive silica minerals in aggregates [1]. The reaction demands an alkaline environment which is found inside the concrete where a natural presence of free calcium hydroxide is found.
    [Show full text]
  • Term Exposure of Different Rebars Used for RC Elements in the Presence of Chloride Conditions
    Uniform and local corrosion characterization and modeling for long- term exposure of different rebars used for RC elements in the presence of chloride conditions Deeparekha Narayanan a, Yi Lua, Ayman Okeilb and Homero Castanedaa a, Department of Materials Science and Engineering, Texas A&M University (TAMU), 400 Bizzell St, College Station, TX 77843. b, Department of Civil and Environmental Engineering, Louisiana State University, 3230J Patrick F. Taylor Hall, Baton Rouge, LA 70803. Abstract. In this work we will present the corrosion behavior of ASTM 615 (steel rebar), ASTM 767 (Steel rebar with hot dip galvanized zinc layer) and ASTM 1094 (steel rebar with continuously galvanized zinc layer) rebars upon long-term exposure in simulated concrete pore solution (SCPS) with 3.5 wt.% NaCl. The rebars corrode in the SPS to form corrosion products on the surface and the chloride in the solution is responsible for the localized attack causing pit formation. The corrosion behavior was monitored continuously by electrochemical methods such as open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). Upon long-term exposure, the surface rebar conditions were characterized assuming uniform corrosion of the rebar due to the aqueous environment. Also, the concentration of NaCl used is beyond the so-called threshold passive breakdown layer in the selected environment. Following different exposure times for the study of localized corrosion, the rebars were characterized for pits and studied the depth distribution of the pits via optical microscopy (OM) The local attack morphologies and a detailed characterization of the pit distribution was carried out by measuring the depths of the identified defects.
    [Show full text]
  • The Basics of Deteriorating Concrete at Wastewater Plants: Tips On
    astewater treatment plants are among the harshest of environments for high-per- formance protective coat- ings. In a wastewater facil- ity, there is never only one cause for a structure to degrade; there are numer- ous causes, and because Wof the multiple causes, once a structure starts to degrade, it does so rapidly. This article gives a basic introduction to, and review of, the chemical and other aggressive exposures within wastewater facilities; how the exposures can cause degradation of a structure; how to diag- nose a corrosion or deterioration problem; The Basics of Deteriorating how to repair the structure; and how to prevent corrosion from recurring. The arti- Concrete at Wastewater Plants: cle will use an example of a wastewater clarifying tank made of hydrated Portland By Heather Bayne, SSPC cement concrete to illustrate the above. Tips on Causes, Repair, and Resources Corrosive Environments Assets,” October 2006, pp. 50–63; sulfate ions, forming sulfide ions, which in Wastewater Treatment Tanks and G. Hall,JPCL, “Out of Sight, Out of Mind, are released back into the wastewater. Wastewater clarifying treatment tanks and Often Out of Order,” October Through chemical reactions in the waste- need to be protected and maintained 2004, pp. 40–48.) JPCL, water system, the sulfide ions combine because their environment exposes with hydrogen to form hydrogen sulfide, them, on a daily basis, to chemical which further reacts and forms hydro- attack, abrasion erosion, chloride ion- SewageChemical in Attack a wastewater storage tank gen sulfide gas. The gas reduces the induced corrosion, and freeze-thaw con- must receive chemical treatment, biologi- pH of the concrete.
    [Show full text]
  • Aging Degradation of Concrete Structures in Nuclear Power Plants
    SKI Report 94:15 Aging Degradation of Concrete Structures in Nuclear Power Plants Mark J. Do and Alan D. Chockie September 1994 ISSN 1104-1374 ISRN SKI-R--94/15--SE SKI Report 94: 15 Aging Degradation of Concrete Structures in Nuclear Power Plants Mark J. Do and Alan D. Chockie Battelle Seattle Research Center, Seattle, Washington 98105 April 1994 This report concerns a study which has been conducted for the Swedish Nuclear Power Inspectorate (SKI). The conclusions and viewpoints presented in the report are those of the author(s) and do not necessarily coincide with those of the SKI. T ABLE OF CONTENTS Executive Summary . .. vii Chapter 1: Introduction ...... .. 1 Chapter 2: The NRC's Aging Research of Concrete ........................ 3 The Structural Aging (SAG) Program ............................. 3 The Nuc1ear Plant Aging Research (NP AR) Program . .. 5 Chapter 3: Functions of Concrete Structures ............................. 7 Safety Significant Concrete Structures ............................. 7 Environmentally Exposed Concrete Structures . .. 9 The Designs of Concrete Containment Structures ..................... 11 Chapter 4: The Sub-structures and Materials of Concrete Containment ........... 21 Sub-structures of Concrete Containments ........................... 21 Materials Used in Concrete Structures ............................. 23 Concrete . .. 23 Conventional Steel Reinforcement . .. 24 Prestressing Steel ...................................... 25 Liner Plate .. .. 25 Embedment Steel .....................................
    [Show full text]
  • Accelerated Carbonation Testing of Alkali-Activated Slag/Metakaolin Blended Concretes: Effect of Exposure Conditions
    This is a repository copy of Accelerated carbonation testing of alkali-activated slag/metakaolin blended concretes: effect of exposure conditions. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/97159/ Version: Accepted Version Article: Bernal, S.A., Provis, J.L. orcid.org/0000-0003-3372-8922, Mejia de Gutierrez, R. et al. (1 more author) (2015) Accelerated carbonation testing of alkali-activated slag/metakaolin blended concretes: effect of exposure conditions. Materials and Structures, 48 (3). pp. 653-669. ISSN 1359-5997 https://doi.org/10.1617/s11527-014-0289-4 Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ This is a postprint of a paper published in Materials & Structures, 48(3):653-669, 2014. The version of record is available at http://dx.doi.org/10.1617/s11527-014-0289-4 1 Accelerated carbonation testing of alkali-activated slag/metakaolin blended 2 concretes: effect of exposure conditions 3 4 Susan A.
    [Show full text]
  • A Review on Alkali-Silica Reaction Evolution in Recycled Aggregate Concrete
    materials Review A Review on Alkali-Silica Reaction Evolution in Recycled Aggregate Concrete Miguel Barreto Santos 1, Jorge De Brito 2,* and António Santos Silva 3 1 School of Technology and Management, Polytechnic of Leiria, Campus 2—Morro do Lena—Alto do Vieiro, 2411-901 Leiria, Portugal; [email protected] 2 CERIS, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1-1049-001 Lisbon, Portugal 3 National Laboratory for Civil Engineering, Av. do Brasil 101, 1700-066 Lisbon, Portugal; [email protected] * Correspondence: [email protected] Received: 7 May 2020; Accepted: 4 June 2020; Published: 9 June 2020 Abstract: Alkali-silica reaction (ASR) is one of the major degradation causes of concrete. This highly deleterious reaction has aroused the attention of researchers, in order to develop methodologies for its prevention and mitigation, but despite the efforts made, there is still no efficient cure to control its expansive consequences. The incorporation of recycled aggregates in concrete raises several ASR issues, mainly due to the difficult control of the source concrete reactivity level and the lack of knowledge on ASR’s evolution in new recycled aggregate concrete. This paper reviews several research works on ASR in concrete with recycled aggregates, and the main findings are presented in order to contribute to the knowledge and discussion of ASR in recycled aggregate concrete. It has been observed that age, exposure conditions, crushing and the heterogeneity source can influence the alkalis and reactive silica contents in the recycled aggregates. The use of low contents of highly reactive recycled aggregates as a replacement for natural aggregates can be done without an increase in expansion of concrete.
    [Show full text]
  • Effect of Alkali-Silica Reaction on Confined Reinforced Concrete
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2020 Effect of Alkali-Silica Reaction on Confined Reinforced Concrete Nolan Wesley Hayes University of Tennessee, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Recommended Citation Hayes, Nolan Wesley, "Effect of Alkali-Silica Reaction on Confined Reinforced Concrete. " PhD diss., University of Tennessee, 2020. https://trace.tennessee.edu/utk_graddiss/5805 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Nolan Wesley Hayes entitled "Effect of Alkali- Silica Reaction on Confined Reinforced Concrete." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Civil Engineering. Z. John Ma, Major Professor We have read this dissertation and recommend its acceptance: Richard M. Bennett, Timothy Truster, Yann Le Pape Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Effect of Alkali-Silica Reaction on Confined Reinforced Concrete A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Nolan Wesley Hayes May 2020 Copyright c by Nolan Wesley Hayes, 2020 All Rights Reserved.
    [Show full text]
  • Materials Properties Model of Aging Concrete
    RECLAMManagAingTWateIr iOn theNWest Report DSO-05-05 Materials Properties Model of Aging Concrete Dam Safety Technology Development Program U.S. Department of the Interior Bureau of Reclamation Technical Service Center Denver, Colorado December 2005 Form Approved REPORT DOCUMENTATION PAGE OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From - To) 12-2005 Technical 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Materials Properties Model of Aging Concrete 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Timothy P. Dolen, P.E. 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT Bureau of Reclamation NUMBER Technical Service Center DSO-05-05 Water Resources Research Laboratory Denver, Colorado 9.
    [Show full text]
  • Mechanical Characteristics and Water Absorption Properties of Blast-Furnace Slag Concretes with Fly Ashes Or Microsilica Additions
    applied sciences Article Mechanical Characteristics and Water Absorption Properties of Blast-Furnace Slag Concretes with Fly Ashes or Microsilica Additions Dora Foti 1,*, Michela Lerna 1, Maria Francesca Sabbà 1 and Vitantonio Vacca 2 1 Polytechnic University of Bari, Department of Civil Engineering Sciences and Architecture (DICAR), Via Orabona 4, 70125 Bari, Italy; [email protected] (M.L.); [email protected] (M.F.S.) 2 National Research Council (CNR), Institute of Environmental Geology and Geo-Engineering, Via Salaria km 29,300, 00015 Montelibretti (Roma), Italy; [email protected] * Correspondence: [email protected]; Tel.: +39-320-171-0524 Received: 20 February 2019; Accepted: 18 March 2019; Published: 27 March 2019 Abstract: The paper shows the results of an experimental tests campaign carried out on concretes with recycled aggregates added in substitution of sand. Sand, in fact, has been totally replaced once by blast-furnace slag and fly ashes, once by blast-furnace slag and microsilica. The aim is both to utilize industrial by-products and to reduce the use of artificial aggregates, which impose the opening of pits with high environmental damage. The results show that in the concretes so made the water absorption capacity has reduced and durability has improved. The test campaign and the results described in the present article are certainly useful and can be especially utilized for research on a larger scale in this field. Keywords: concrete; aggregates; fly-ash; silica fume; blast-furnace slag; mechanical properties; water absorption 1. Introduction In recent times, the problem of preservation of reinforced and pre-stressed concrete structures has been developing rapidly.
    [Show full text]