DOCSLIB.ORG

Strengthening of Concrete Structures by the Use of Mineral-Based Composites

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Strengthening of Concrete Structures by the Use of Mineral-Based Composites ISSN: 1402-1544 ISBN 978-91-86233-XX-X Se i listan och fyll i siffror där kryssen är DOCTORAL T H E SIS Thomas Blanksvärd Department of Civil and Environmental Engineering Division of Structural Engineering Strengthening of concrete structures ISSN: 1402-1544 ISBN 978-91-86233-23-5 by the use of mineral-based composites Luleå University of Technology 2009 System and design models for flexure and shear Strengthening of concrete structures by the use of mineral-based composites System and design models for flexure and shear Thomas Blanksvärd Luleå University of Technology DOCTORAL THESIS Strengthening of concrete structures by the use of mineral- based composites System and design models for flexure and shear Thomas Blanksvärd Luleå University of Technology Department of Civil, Mining and Environmental Engineering Division of Structural Engineering SE - 971 87 Luleå Sweden www.ltu.se/shb “The roots of education are bitter, but the fruit is sweet” ȡȚıIJȠIJȑȜȘȢں // Strengthening of concrete structures by the use of mineral-based composites Strengthening of concrete structures using mineral-based composites THOMAS BLANKSVÄRD 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 24 april 2009, klockan 10.00 Fakultetsopponent: Professor Thanasis C. Triantafillou, Department of Civil Engineering, University of Patras, Patras Greece Betygsnämnd: Professor Henrik Stang, Department of Civil Engineering, Technical University of Denmark, Lyngby Denmark. Professor Timo Aho, Department of Construction Technology, Oulu University, Oulu, Finland. Professor emeritus Ralejs Tepfers, Avdelningen för konstruktionsteknik, Chalmers tekniska högskola, Göteborg Sverige. Docent Kjell Eriksson, Avdelningen för hållfasthetslära, Luleå tekniska universitet, Luleå Sverige. Tekn. Dr. Anders Wiberg, Anläggningsunderhåll, Grontmij, Stockholm Sverige. Tryck: Universitetstryckeriet, Luleå ISBN: 978-91-86233-23-5 ISSN 1402-1544 Luleå 2009 www.ltu.se Front page: The illustration shows concrete members strengthened in shear and bending. The member strengthened in shear is in the front since more time was spent on exploring the aspects of shear strengthening using mineral-based composites (MBC). The filmstrip at the bottom shows applications of the MBC system starting from the inside of a silo to strengthening of balconies. Preface Preface Every expedition has to have a purpose and a defined finishing line. My exploration journey as a PhD student started in September 2004. The official purpose with this mission was to investigate the suitability of using mineral-based composites for strengthening of existing concrete structures. During the last four and a half years I have learned that the unofficial purpose with this expedition was to explore my own suitability as a researcher and how to strengthen myself as an individual. The outcome of all expeditions is highly dependent on the surrounding environment, people and finances. I would therefore like to extend my personal gratitude to the following: For the financial support I am grateful to the Swedish Road Administration, the Development Fund of the Swedish Construction Industry (SBUF), Skanska Sverige AB, the European Integrated Project “Sustainable Bridges” and Sto Scandinavia AB. Elsa and Sven Thysell’s foundation, Maj and Hidling Brosénius Foundation, Wallenberg Fundation and Ångpanneföreningen are appreciated for scholarships enabling me to travel outside Sweden to present my research and make new friends. Prof. Björn Täljsten, I have travelled the world under your wings and gathered knowledge not possible elsewhere. Thanks for being both a friend and firm supervisor, I hope to work with you in the future. Dr Anders Carolin, the deputy supervisor, for all on and off topic conversations and being a great mentor. The laboratory investigations would not have been possible without the helpful members in the lab, Mr. Håkan Johansson, Civ Eng. Georg Danielsson, Mr. Lars Åström, Mr. Thomas Forsberg and Dr. Claes Fahlesson The staff at the division of Structural Engineering with its head Prof. Mats Emborg, for bringing me diversity in conversations and festivities. I would also like to send a special thought to my colleagues and friends in the research group “Innovative Materials and Structures” Gabbe, Mackan and Bennitz for all the help and support. I mentioned that my expedition started in 2004, this was not entirely true. I have followed my father in the laboratory ever since I learned to walk. During my early missions in the division of Structural Engineering I met Prof. Lennart Elfgren who has given me insightful comments during my entire visit at the university. So thank you Dad for giving me confidence, showing me that the university was not a scary place and for all the useful and endless discussions regarding civil engineering I would also like to extend my gratitude to my mom, brother and sister for always being there, believing in me and defining me as a person. I Strengthening of concrete structures by the use of mineral-based composites When the academic environment became too dull, I took refuge in my band SlideShow. Thank you Poe Deprey, Foxy Black and Nicky Dollars for living the rock n roll life style with me. Saved for last, the most important dynamic factor in my life is my wife. With your everlasting energy you bring colour and shape to the otherwise grey and square subsistence. Thank you for being you and always understanding that sometimes it requires 18h days to finish a PhD. If I need help with notations or to do NSMR strengthening, you are always first in line. - Multiply it by infinity, take it to the depths of forever and you will still only have a glimpse of how much I love you. This concludes my seemingly 30 year long expedition in the jungle called Luleå University of Technology. Now, it is off in to the horizon and beyond. Thomas Blanksvärd April 2009 II Summary Summary A great number of society’s resources are invested in existing concrete structures, such as bridges, tunnels, different kind of buildings etc. All of these structures have both an expected function and an expected life span. However, both the function and the life span can be influenced by external factors, e.g. degradation and altered load situations. Further influencing aspects could be mistakes in design or during the construction phase. Repairing and/or strengthening these structures could maintain or increase the function as well as the life span. To strengthen concrete structures by using adhesively bonded fibres or fibre reinforced polymers (FRP) has been shown to be an excellent way of improving the load bearing capacity. The most common adhesive used for this type of strengthening is epoxies. Unfortunately, there are some drawbacks with the use of epoxy adhesives such as diffusion tightness, poor thermal compatibility with concrete and requirements for a safe working environment which might lead to allergic reactions if proper protective clothing is not used. A further limiting factor is the requirement on the surrounding temperature at application. A commonly recommended minimum temperature at the time for application is 10°C, which makes the preparations regarding application during colder seasons much more complicated. However, some of these drawbacks could be reduced by substituting the epoxy adhesive for a mineral-based bonding agent with similar material properties as concrete. The strengthening system and also the topic of this thesis is termed “mineral-based composites” (MBC). The MBC consists in this context of grids of carbon FRP with high tensile strength that are bonded to an existing concrete surface by the use of a cement based bonding agent. The scientific approach in this thesis includes analytical methods to describe load bearing capacity for the strengthened concrete structure in both flexure and shear. The analytical approaches are then verified against experimental results. Above the theoretical and experimental performance of the MBC system a review of state of the art research has been made in order to collate and map existing mineral-based strengthening systems other than the MBC system. To develop and verify the theoretical models and to compare the performance of the MBC system to other possible designs of mineral-based strengthening systems, six papers are appended in the thesis. III Strengthening of concrete structures by the use of mineral-based composites - The first paper describes the performance of the MBC system when used in flexural strengthening. The experimental program in this paper consists of a concrete slab strengthened with both the MBC system and epoxy based system. In addition, a parametric study was made on small scale beam specimens to evaluate the performance of using different cement-based bonding agents. - The second paper describes the performance of the MBC system when used as shear strengthening. This study consists of experimental results of 23 reinforced concrete beams with different concrete qualities, internal shear reinforcement ratios together with different variations of the CFRP grid design and mineral- based bonding agents. In addition, a comparison is also made to traditional epoxy-based strengthening. This paper also has an analytical approach to estimate the shear resistance. - The third
Load more

Recommended publications
  • Guide to Concrete Repair Second Edition
    ON r in the West August 2015 Guide to Concrete Repair Second Edition Prepared by: Kurt F. von Fay, Civil Engineer Concrete, Geotechnical, and Structural Laboratory U.S. Department of the Interior Bureau of Reclamation Technical Service Center August 2015 Mission Statements The U.S. Department of the Interior protects America’s natural resources and heritage, honors our cultures and tribal communities, and supplies the energy to power our future. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Acknowledgments Acknowledgment is due the original author of this guide, W. Glenn Smoak, for all his efforts to prepare the first edition. For this edition, many people were involved in conducting research and field work, which provided valuable information for this update, and their contributions and hard work are greatly appreciated. They include Kurt D. Mitchell, Richard Pepin, Gregg Day, Jim Bowen, Dr. Alexander Vaysburd, Dr. Benoit Bissonnette, Maxim Morency, Brandon Poos, Westin Joy, David (Warren) Starbuck, Dr. Matthew Klein, and John (Bret) Robertson. Dr. William F. Kepler obtained much of the funding to prepare this updated guide. Nancy Arthur worked extensively on reviewing and editing the guide specifications sections and was a great help making sure they said what I meant to say. Teri Manross deserves recognition for the numerous hours she put into reviewing, editing and formatting this Guide. The assistance of these and numerous others is gratefully acknowledged. Contents PART I: RECLAMATION'S METHODOLOGY FOR CONCRETE MAINTENANCE AND REPAIR Page A.
    [Show full text]
  • Reinforcing Steel Cover When Reinforcing Steel Is Too Close to the Surface, It Begins Rusting and Expanding, Causing the Surrounding Concrete to Break Away
    BRANZ FACTS MID-RISE BUILDINGS #4 Exposed issues – reinforcing steel cover When reinforcing steel is too close to the surface, it begins rusting and expanding, causing the surrounding concrete to break away. STEEL REINFORCING BARS are used in concrete and concrete masonry to provide resistance to tensile loads and for concrete slabs and panels to help limit the risk of shrinkage cracking as the material cures. The steel relies on being sufficiently deep (called cover) within the concrete to protect it from moisture and corrosion. Where it is too close to the surface or the concrete is poor quality, it will begin rusting. As steel rusts, it expands, and this can result in concrete spalling – where pieces of concrete are broken away by the expanding steel. As the concrete breaks away or cracks, more moisture can get in and the deterioration will accelerate. The corrosion will also reduce the tensile strength of the steel as the steel deteriorates. How much cover? How much cover depends on: NZS 4229:2013 Concrete masonry buildings Tables 1 and 2 outline the requirements ● what the steel is embedded in – concrete not requiring specific engineering design: from NZS 3101.1&2:2006 Concrete structures or the grouted cells of concrete masonry ● For concrete masonry: standard. ● concrete or grout strength • 45 mm in exposure zone B For concrete masonry structures built to ● what the surface of the concrete is • 50 mm in exposure zone C NZS 4229:2013, the cover requirements from exposed to – soil or air • 60 mm in exposure zone D. the external face of uncoated masonry are: ● the corrosion or environmental zone ● For concrete: ● for exposure zone B – 45 mm with 17.5 ● the type of steel used – mild steel, • 75 mm for concrete placed directly on MPa grout galvanised, stainless steel or against the ground (can be reduced ● for exposure zone C – 50 mm with 20 ● intended life of the structure to 50 mm where there is a DPM MPa grout ● cement type.
    [Show full text]
  • Reinforcing Footings Cover Do You Know the Minimum Bending Diameter for Reinforcing Steel and Its Cover
    MINIMUM DIMENSIONS AND COVER FOR CONCRETE FOOTINGS WITH REINFORCING STEEL BUILD RIGHT Reinforcing footings cover Do you know the minimum bending diameter for reinforcing steel and its cover BY TREVOR PRINGLE, requirements in concrete footings? This determines the minimum width you ANZIA, BRANZ PRINCIPAL need to make your concrete footings. WRITER SOME DIMENSIONS GIVEN in NZS 3604:2011 Bending diameters 5 × bar diameter ● the bar diameter Timber-framed buildings for reinforced concrete For foundation walls to concrete slabs, the ● the bar bend diameter. foundation footings may be insufficient. This horizontal bars are typically D12 and the is due to the bending diameters and minimum vertical starter bars are R10. Two D12s stacked concrete cover required for steel reinforcing in Minimum bending diameters for reinforcing For a foundation non-cantilevered wall using concrete footings. steel are given in Tables 8.1 and 8.2 of NZS two D12s horizontally with R10s vertically, the 3101.1&2:2006 Concrete structures standard. minimum width (see Figure 1) will be: Footing widths in NZS 3604:2011 According to Table 8.1, the bending diameter ● cover on each side: 2 × 75 mm = 150 mm NZS 3604:2011 section 7.5 sets out require- for 6–20 mm diameter deformed and plain ● vertical bar diameter: 2 × 10 mm = 20 mm ments for reinforced concrete foundation walls steel reinforcing bars must be at least five ● minimum bend diameter: 5 × 10 mm = and footings for concrete slabs on ground. times the bar diameter. Therefore, the 50 mm. Figures 7.13(B), 7.14(B and C) and 7.16 (B and C) reinforcing bar minimum bending diameter This gives a minimum foundation width of give minimum footing width dimensions.
    [Show full text]
  • Flexural Cracking in Concrete Structures
    22 TRANSPORTATION RESEARCH RECORD 1301 Flexural Cracking in Concrete Structures EDWARD G. NAWY The state-of-the-art in the evaluation of the flexural crack width Although the macrocracking aspects of cracking behavior development and crack control of macrocracks is described. It is are emphasized, it is also important to briefly discuss micro­ based on extensive research over the past 50 years in the United cracking. States and overseas in the area of macrocracking in reinforced and prestressed concrete beams and two-way-action slabs and plates. Control of cracking has become essential to maintain the integrity and aesthetics of concrete structures. The trends are MICROCRACKING stronger than ever-toward better use of concrete strength, use of higher-strength concretes including superstrength concretes of over 20,000-psi compressive strength, use of more prestressed Microcracking can be mainly classified into two categories: concretes, and increased use of limit failure theories-all re­ (a) bond cracks at the aggregate-mortar interface, and (b) quiring closer control of serviceability requirements of cracking paste cracks within the mortar matrix. Interfacial bond cracks and deflection behavior. Common expressions are discussed for are caused by interfacial shear and tensile stresses caused by the control of cracking in reinforced-concrete beams and thick early volumetric change without the presence of external load. one-way slabs; prestressed, pretensioned, and posttensioned flanged Volume change caused by hydration and shrinkage could cre­ beams; and reinforced-concrete, two-way-action, structural floor slabs and plates. In addition, recommendations are given for the ate tensile and bond stresses of sufficient magnitude to cause maximum tolerable flexural crack widths in concrete elements.
    [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]
  • SECTION 03300 CAST-IN-PLACE CONCRETE PART 1 GENERAL 1.01 SUMMARY A. This Section Covers Formwork, Reinforcing Steel, and Cast-In
    SECTION 03300 CAST-IN-PLACE CONCRETE PART 1 GENERAL 1.01 SUMMARY A. This section covers formwork, reinforcing steel, and cast-in-place Concrete work. B. Related Work Specified Elsewhere 1. Manholes: Section 02605 2. Storm Sewer Collection System: Section 02722 C. Measurement and Payment Procedures 1. For public funded capital improvement projects, measurement and payment procedures will be determined on a project by project basis. 2. For privately funded development projects, Owner will determine measurement and payment requirements. 1.02 REFERENCES A. American Concrete Institute (ACI) International 1. ACI 305 – Hot Weather Concreting 2. ACI 306 – Cold Weather Concreting 3. ACI 309 – Standard Practice for Consolidation of Concrete 4. ACI 318 – Building Code Requirements for Structural Concrete and Commentary B. American Society for Testing and Materials (ASTM) 1. ASTM A82 – Standard Specification for Steel Wire, Plain, for Concrete Reinforcement 2. ASTM A185 – Specification for Steel Welded Wire Fabric, Plain, for Concrete Reinforcement 3. ASTM A615 – Deformed and Plain Billet-Steel Bars for Concrete Reinforcement 4. ASTM A996 – Specification for Rail-Steel and Axle-Steel Deformed Bars for Concrete Reinforcement 5. ASTM C31 – Making and Curing Concrete Test Specimens in the Field 6. ASTM C33 – Concrete Aggregates 7. ASTM C39 - Compressive Strength of Cylindrical Concrete Specimens 8. ASTM C94 – Ready-Mixed Concrete 9. ASTM C143 – Slump of Hydraulic Cement Concrete 10. ASTM C150 – Portland Cement 11. ASTM C171 – Sheet Materials for Curing Concrete 12. ASTM C231 – Air Content of Freshly Mixed Concrete by the Pressure Method. 13. ASTM C260 – Air-Entraining Admixtures for Concrete 14. ASTM C309 – Liquid Membrane-Forming Compounds for Curing Concrete 15.
    [Show full text]
  • The Symposium Took Place 13Th to 15Th August 2014
    PUBLICATION NO. 50 2/2014 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 PROCEEDING XXII NORDIC CONCRETE RESEARCH SYMPOSIA REYKJAVIK, ICELAND 2014 iii PUBLICATION NO. 50 2/2014 CONTENTS OPENING SESSION 1 Tor Arne Martius-Hammer 3 COIN - Main Achievements 1 DURABILITY, MAINTENANCE, RENOVATION & FROST ACTION - 7 PER FIDJEST0L MEMORIAL SESSION R. Doug Hooton 9 Advantages of Silica Fume-Slag Ternary Binders for Production of Dura¬ ble Concrete Olafur H. Wallevik, Indri6i Nielsson & Bjorn Hjartarson 13 Self-compacting concrete without chemical admixture for Per Fidjestol Martin Kaasgaard, Claus Pade, UlfJonsson & Christian Munch-Petersen 17 Comparison of Durability Parameters of Self-Compacting Concrete and Conventional Slump Concrete Designed for Marine Environment Marianne Tange Hasholt 21 The Interplay Between Inner and Outer Frost Damage and its Implication for Accelerated Freeze-Thaw Testing Jonny Nilimaa, Jens Haggstrom, Niklas Bagge, Thomas Blanksvard, Gabriel 25 Sas, Ulf Ohlsson, Lars Bernspang, Bjorn Taljsten, Lennart Elfgren, Anders Carolin, Hakan Thun & Bjorn Paulsson Maintenance and Renewal of Concrete Rail Bridges - Results from EC Project MAINLINE 2 STRUCTURAL BEHAVIOUR AND DESIGN 29 Tarek Edrees Saaed, George Nikolakopoulos & Jan-Erik Jonasson 31 Semi-Active Structural Control Strategies Linn Grepstad Nes & Jan Arve 0verli 35 Structural Behaviour of Beams with Fibre Reinforced LWAC and Normal Density Concrete Mario Plos, Costin Pacoste & Morgan Johansson 39 Recommendations for Finite Element Analysis for Design of RC Slabs Havard Nedrelid & Terje Kanstad 43 Tests and Design of Fibre-Reinforced RC Beams with Dapped Ends Morten Engen, Max A.
    [Show full text]
  • Architectural Precast Concrete Wall Panels: Their Technological Evolution, Significance, and Preservation
    University of Pennsylvania ScholarlyCommons Theses (Historic Preservation) Graduate Program in Historic Preservation 2016 Architectural Precast Concrete Wall Panels: Their Technological Evolution, Significance, and Preservation Grace Meloy University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/hp_theses Part of the Historic Preservation and Conservation Commons Meloy, Grace, "Architectural Precast Concrete Wall Panels: Their Technological Evolution, Significance, and Preservation" (2016). Theses (Historic Preservation). 608. https://repository.upenn.edu/hp_theses/608 Suggested Citation: Meloy, Grace (2016). Architectural Precast Concrete Wall Panels: Their Technological Evolution, Significance, and Preservation. (Masters Thesis). University of Pennsylvania, Philadelphia, PA. This paper is posted at ScholarlyCommons. https://repository.upenn.edu/hp_theses/608 For more information, please contact [email protected]. Architectural Precast Concrete Wall Panels: Their Technological Evolution, Significance, and Preservation Abstract Architectural precast concrete wall panels played an important role in mid-twentieth century architecture by providing a concrete technology that could be applied to the curtain wall system of construction utilized in this time period. Moreover, the precasting process, which enabled the controlled production of expressive facing concrete mixes and surface treatments and finishes, made this a concrete technology that could contribute to the architectural
    [Show full text]
  • ACI 302.1R-15: Guide to Concrete Floor
    The attached excerpted resource materials have been made available for use within ACI University. To obtain a full version of this document, please visit the ACI Store. For additional education products, please visit ACI University. ACI 302.1R-15 Guide to Concrete Floor and Slab Construction Reported by Committee 302 Joseph F. Neuber Jr., Chair Russell E. Neudeck, Secretary Patrick J. Harrison, Vice Chair Dennis C. Ahal Jerry A. Holland Nigel K. Parkes Carl Bimel* Bryan M. Birdwell Philip S. Kopf William S. Phelan Michael A. Clark Peter A. Craig Steve R. Lloyd, Sr. Tim H. Robinson William C. Panarese Allen Face Kevin A. MacDonald John W. Rohrer Brian J. Pashina C. Rick Felder Arthur W. McKinney Paul A. Rouis, III Boyd C. Ringo* Edward B. Finkel Donald M. McPhee Domenick Thomas Ruttura Barry E. Foreman Scott C. Metzger Bruce A. Suprenant *Deceased Greg K. Fricks Jeffrey S. Miller Scott M. Tarr Terry J. Fricks Scott L. Niemitalo Consulting Members The quality of a concrete floor or slab is highly dependent on on every project, and that such an occurrence does not necessarily achieving a hard and durable surface that is flat, relatively free reflect adversely on either the adequacy of the floor’s design or the of cracks, and at the proper grade and elevation. Properties of the quality of its construction (Ytterberg 1987). surface are determined by the mixture proportions and the quality This guide describes how to produce high-quality concrete slabs- of the concreting and jointing operations. The timing of concreting on-ground and suspended floors for various classes of service.
    [Show full text]
  • ASR) and Alkali-Carbonate Reaction (ACR)
    ALKALI-SILICA REACTIVITY FIELD IDENTIFICATION HANDBOOK Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. FHWA-HIF-12-022 4. Title and Subtitle 5. Report Date Alkali-Silica Reactivity Field Identification Handbook December 2011 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Thomas, M.D.A., Fournier, B., Folliard, K.J., Resendez, Y.A. 9. Performing Organization Name and Address 10. Work Unit No. The Transtec Group, Inc. 6111 Balcones Drive Austin, TX 78731 11. Contract or Grant No. DTFH61-06-D-00035 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Office of Pavement Technology Final Report December 2011 Federal Highway Administration 1200 New Jersey Avenue, DE Washington, DC 20590 14. Sponsoring Agency Code 15. Supplementary Notes Contracting Officer’s Technical Representative (COTR): Gina Ahlstrom, HIPT-20 16. Abstract Two types of alkali-aggregate reaction (AAR) are currently recognized depending on the nature of the reactive mineral; these are alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR). Both types of reaction can result in expansion and cracking of concrete elements, lead­ ing to a reduction in the service life of concrete structures. This handbook serves as an illustrated guide to assist users in detecting and distin­ guishing ASR in the field from other types of damages. 17. Key Words 18. Distribution Statement Alkali-silica reactivity, alkali-aggregate reaction, reactive No restrictions. This document is available to the public through the Na­ aggregates, concrete durability, field identification, concrete tional Technical Information Service, Springfield, VA 22161.
    [Show full text]
  • Enhanced Mechanical and Durability Performances of Low Cement Concrete with Natural Pozzolan Addition
    Journal of Advanced Concrete Technology Vol. 19, 519-535, May 2021 / Copyright © 2021 Japan Concrete Institute 519 Scientific paper Enhanced Mechanical and Durability Performances of Low Cement Concrete with Natural Pozzolan Addition Keila Robalo1, Hugo Costa2*, Ricardo do Carmo3 and Eduardo Júlio4 Received 6 November 2020, accepted 3 May 2021 doi:10.3151/jact.19.519 Abstract The decarbonization of concrete structures sector is a priority due to the world climate. Since Portland cement is re- sponsible for approximately 7% of the anthropogenic emissions worldwide, it is decisive to partially replace it by prod- ucts with lower environmental impact. Fly ash has become highly demanded, due to its proven advantages, however, has announced end by the developed countries. The purpose of this research is to develop and characterize low cement concrete (LCC) with natural and ecological pozzolan additions as an alternative to fly ash. The main objectives are: define several structural concrete mixtures with low cement dosage, ranging from 125 to 175 kg/m3; characterize the workability and the mechanical properties, beyond the durability performance of those concretes; study the influence of pozzolans additions on LCC performance, as an alternative to fly ash; assess the service life of structures produced with the developed LCC. It is possible to produce LCC with natural pozzolan additions, instead of fly ash, with improved mechanical properties and enhanced durability performances. Results also show that the structural LCC produced with pozzolan from Cape Verde provide a great protection against steel corrosion, achieving values 50% higher than concrete with fly ash, and even higher margins when compared with the minimum concrete covers recommended by standards, which highlights the benefits of its use from the sustainability point of view.
    [Show full text]
  • Sustainable Benefits of Concrete Structures
    Copyright: Foreword European Concrete Platform ASBL, February 2009 Sustainability lies at the heart of construction and design. A sustainable approach of construction brings lasting environmental, All rights reserved. No part of this publication may be re- produced, stored in a retrieval system or transmitted in social and economic benefits to a construction project. From that any form or by any means, electronic, mechanical, perspective, concrete achieves high valuable properties as a con- photocopying, recording or otherwise, without the prior struction material limiting the impacts of a building or infrastructure written permission of the European Concrete Platform on its surroundings. ASBL. Published by the European Concrete Platform ASBL Acknowledgements Editor: Jean-Pierre Jacobs 1050 Brussels, Belgium This was originally written and published in 2007 by the Environ- Layout & graphic design: Geert Joostens bvba JO-OP mental Working Group of Betonikeskus ry, in Finland, under the title Printing by the European Concrete Platform ASBL Environmental properties of concrete structures. All information in this document is deemed to be ac- We thank Laetitia Dévant for her work Europeanizing the book, the curate by the European Concrete Platform ASBL at the English Centre for the translation, the British Precast (particularly time of going into press. It is given in good faith. Martin Clarke and Chrissie Walton), Gillian Bond and Brian O’Murchu Information on European Concrete Platform documents for their revisions, and Geert Joostens for his inspired and insightful does not create any liability for its Members. While the goal is to keep this information timely and accurate, the design. European Concrete Platform ASBL cannot guarantee We pay all due respect to all the people from the European Con- either.
    [Show full text]