Download or read book Evaluation of High Absorptive Materials to Improve Internal Curing of Low Permeability Concrete written by Norbert J. Delatte and published by . This book was released on 2007 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early age cracking of bridge decks is a national problem, and may substantially reduce service lives and increase maintenance costs. Cracking occurs when the tensile stress exceeds the tensile strength of the concrete. This is a time-dependent phenomenon, since both the stress and strength change at early ages. Moisture loss increases stress (with increasing shrinkage) and impairs strength gain. Internal curing is one method that has been suggested to reduce early age bridge deck cracking, particularly of concretes with low water to cementitious materials (w/cm) ratios. Many state highway agencies have implemented high performance concrete (HPC) for bridge decks. The low permeability of HPC is used to protect reinforcing steel and prevent corrosion. However, if the concrete cracks, then the protection may be greatly diminished. Transverse cracks due to concrete shrinkage allow water and corrosive chemicals to quickly reach the reinforcing steel causing corrosion and shortening the lifespan of the bridge deck. Reducing shrinkage cracking has been the focus of recent research into mitigation strategies. One unintended consequence of the use of high performance concrete may be early-age cracking. Field studies have shown that, in some cases, high performance concrete bridge decks have cracked less than a year after placement. The use of internal curing to reduce autogenous shrinkage was investigated in this study. One method of internal curing was through the use of coarse aggregates with high absorption capacities. Another method discussed is the use of a partial replacement of the fine aggregate with a structural lightweight aggregate with a very high absorption capacity. Bridge deck cracking is also affected by the nominal maximum size coarse aggregate. The effect on shrinkage with increasing size is discussed. ODOT's District 12, located in Northeastern Ohio, found in an investigation of 116 HPC bridge decks placed between 1994 and 2001 that bridges with little or no cracking used coarse aggregate with an absorption> 1 %, while 75 % of bridges with unacceptable cracking used coarse aggregate with absorption 1 %. This report discusses the laboratory investigation of the field results to determine the better ways to prevent bridge deck cracking-- internal curing or paste reduction by using an aggregate blend. The laboratory investigation found that the strongest effect on cracking was due to the replacement of a small maximum size coarse aggregate with an optimized coarse aggregate gradation. Increasing the coarse aggregate absorption level from

Download or read book Creep Shrinkage and Durability Mechanics of Concrete and Concrete Structures Two Volume Set written by Tada-aki Tanabe and published by CRC Press. This book was released on 2008-09-01 with total page 1540 pages. Available in PDF, EPUB and Kindle. Book excerpt: CREEP, SHRINKAGE AND DURABILITY MECHANICS OF CONCRETE AND CONCRETE STRUCTURES contains the keynote lectures, technical reports and contributed papers presented at the Eighth International Conference on Creep, Shrinkage and Durability of Concrete and Concrete Structures (CONCREEP8, Ise-shima, Japan, 30 September - 2 October 2008). The topics covered

Download or read book Curing Concrete written by Peter C. Taylor and published by CRC Press. This book was released on 2013-09-10 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Curing is one of those activities that every civil engineer and construction worker has heard of, but in reality does not worry about much. In practice, curing is often low on the list of priorities on the construction site, particularly when budgets and timelines are under pressure. Yet the increasing demands being placed on concrete mixtures also

Download or read book Improving Pavement and Bridge Deck Performance written by National Research Council (U.S.). Highway Research Board. Western Summer Meeting and published by Transportation Research Board National Research. This book was released on 1971 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This issue of HRB Special Report contains the papers presented at the Western Summer Meeting, held in Sacramento, California and is organized into three categories. The first group are papers that attempt to identify some of the factors contributing to the deterioration of concrete bridge decks. The second group addresses the general subject of evaluating pavement serviceability and performance. The third group investigates the design and construction of overlays and surface treatments for pavement rehabilitation.

Download or read book Advanced Concretes and Their Structural Applications written by Zhigang Zhang and published by Frontiers Media SA. This book was released on 2022-09-23 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bridge Maintenance Safety Management Life Cycle Sustainability and Innovations written by Hiroshi Yokota and published by CRC Press. This book was released on 2021-04-20 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations contains lectures and papers presented at the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), held in Sapporo, Hokkaido, Japan, April 11–15, 2021. This volume consists of a book of extended abstracts and a USB card containing the full papers of 571 contributions presented at IABMAS 2020, including the T.Y. Lin Lecture, 9 Keynote Lectures, and 561 technical papers from 40 countries. The contributions presented at IABMAS 2020 deal with the state of the art as well as emerging concepts and innovative applications related to the main aspects of maintenance, safety, management, life-cycle sustainability and technological innovations of bridges. Major topics include: advanced bridge design, construction and maintenance approaches, safety, reliability and risk evaluation, life-cycle management, life-cycle sustainability, standardization, analytical models, bridge management systems, service life prediction, maintenance and management strategies, structural health monitoring, non-destructive testing and field testing, safety, resilience, robustness and redundancy, durability enhancement, repair and rehabilitation, fatigue and corrosion, extreme loads, and application of information and computer technology and artificial intelligence for bridges, among others. This volume provides both an up-to-date overview of the field of bridge engineering and significant contributions to the process of making more rational decisions on maintenance, safety, management, life-cycle sustainability and technological innovations of bridges for the purpose of enhancing the welfare of society. The Editors hope that these Proceedings will serve as a valuable reference to all concerned with bridge structure and infrastructure systems, including engineers, researchers, academics and students from all areas of bridge engineering.

Download or read book Damage to Concrete Structures written by Geert De Schutter and published by CRC Press. This book was released on 2017-06-29 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: Serious degradation mechanisms can severely reduce the service life of concrete structures: steel reinforcement can corrode, cement matrix can be attacked, and even aggregates can show detrimental processes. Therefore, it is important to understand how damage can occur to concrete structures and to appreciate the timing of the actions leading to damage. Damage to Concrete Structures summarizes the state-of-the-art information on the degradation of concrete structures, and gives a clear and comprehensive overview of what can go wrong. Offering a logical flow, the chapters are ordered according to the chronological timing of the actions leading to concrete damage. The author explains the different actions or mechanisms in a fundamental manner, without too many physical or chemical details, to provide greater clarity and readability. The book describes the different causes of damage to concrete, including inappropriate design, errors during execution, mechanisms occurring during hardening of concrete, and actions or degradation mechanisms during service life (hardened concrete). The degradation mechanisms are illustrated with numerous real-world examples and many drawings and photographs taken of actual structures. Written as a textbook for students as well as a reference for professionals, this easy-to-comprehend book gives readers a deeper understanding of the damage that can occur to concrete during the construction process and service.

Download or read book Concrete Permeability and Durability Performance written by Roberto J. Torrent and published by CRC Press. This book was released on 2021-12-22 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: Durability and service life design of concrete constructions have considerable socio-economic and environmental consequences, in which the permeability of concrete to aggressive intruders plays a vital role. Concrete Permeability and Durability Performance provides deep insight into the permeability of concrete, moving from theory to practice, and presents over 20 real cases, such as Tokyo’s Museum of Western Art, Port of Miami Tunnel and Hong Kong-Zhuhai-Macao sea-link, including field tests in the Antarctic and Atacama Desert. It stresses the importance of site testing for a realistic durability assessment and details the "Torrent Method" for non-destructive measurement of air-permeability. It also delivers answers for some vexing questions: Should the coefficient of permeability be expressed in m2 or m/s? How to get a "mean" pore radius of concrete from gas-permeability tests? Why should permeability preferably be measured on site? How can service life of reinforced concrete structures be predicted by site testing of gas-permeability and cover thickness? Practitioners will find stimulating examples on how to predict the coming service life of new structures and the remaining life of existing structures, based on site testing of air-permeability and cover thickness. Researchers will value theoretical principles, testing methods, as well as how test results reflect the influence of concrete mix composition and processing.

Download or read book High Performance Structural Fibers for Advanced Polymer Matrix Composites written by National Research Council and published by National Academies Press. This book was released on 2005-06-09 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Military use of advanced polymer matrix composites (PMC)â€"consisting of a resin matrix reinforced by high-performance carbon or organic fibersâ€"while extensive, accounts for less that 10 percent of the domestic market. Nevertheless, advanced composites are expected to play an even greater role in future military systems, and DOD will continue to require access to reliable sources of affordable, high-performance fibers including commercial materials and manufacturing processes. As a result of these forecasts, DOD requested the NRC to assess the challenges and opportunities associated with advanced PMCs with emphasis on high-performance fibers. This report provides an assessment of fiber technology and industries, a discussion of R&D opportunities for DOD, and recommendations about accelerating technology transition, reducing costs, and improving understanding of design methodology and promising technologies.

Download or read book Internal Curing a 2010 State Of the Art Review written by nist and published by . This book was released on 2013-11-26 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The American Concrete Institute in 2010 defined internal curing as supplying water throughout a freshly placed cementitious mixture using reservoirs, via pre-wetted lightweight aggregates, that readily release water as needed for hydration or to replace moisture lost through evaporation or self-desiccation (American Concrete Institute, 2010). While internal curing has been inadvertently included in many lightweight concretes produced within the past 100 years, it is only within the first decade of the 21st century that this technology has been intentionally incorporated into concrete mixtures at the proportioning stage, using a variety of materials including pre-wetted lightweight aggregates, pre-wetted crushed returned concrete fines, superabsorbent polymers, and pre-wetted wood fibers. This report provides a state-of-the-art review of the subject of internal curing, first addressing its history and theory, andthen proceeding to summarize published guidance on implementing internal curing in practice and published research on its influence on the performance properties of concrete. The ongoing exploration of extensions of the internal curing concept that employ the internal reservoirs to contain materials other than water are reviewed. Finally, the critical issue of sustainability is addressed. An extensive internal curing bibliography that is also available over the Internet is included in an appendix. The report is mainly focused on the utilization of prewettedlightweight aggregates as the internal reservoirs due to thisbeing the current established practice within the U.S.

Download or read book Concrete Mixture Proportioning written by Francois de Larrard and published by CRC Press. This book was released on 1999-03-04 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of concrete mixes is becoming increasingly complex, with the addition of new materials in the compounds, such as organic admixtures, fibres and supplementary cementitious materials. Moreover, the list of properties which concretes are required to possess for certain applications has increased, and interest is developing in rheology, durability, deformability and whole-life behaviour. This book presents a number of simple models for the understanding of a concrete system, and provides the techniques for developing more sophisticated models for the practical design of concrete mixes.

Download or read book Standard Practice for Concrete written by United States. Army. Corps of Engineers and published by . This book was released on 1974 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Application of Super Absorbent Polymers SAP in Concrete Construction written by Viktor Mechtcherine and published by Springer Science & Business Media. This book was released on 2012-01-03 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the state-of-the-art report prepared by the RILEM TC “Application of Super Absorbent Polymers (SAP) in concrete construction”. It gives a comprehensive overview of the properties of SAP, specific water absorption and desorption behaviour of SAP in fresh and hardening concrete, effects of the SAP addition on rheological properties of fresh concrete, changes of cement paste microstructure and mechanical properties of concrete. Furthermore, the key advantages of using SAP are described in detail: the ability of this material to act as an internal curing agent to mitigate autogenous shrinkage of high-performance concrete, the possibility to use SAP as an alternative to air-entrainment agents in order to increase the frost resistance of concrete, and finally, the benefit of steering the rheology of fresh cement-based materials. The final chapter describes the first existing and numerous prospective applications for this new concrete additive.

Download or read book Creep and Shrinkage in Concrete Structures written by Z. P. Bažant and published by John Wiley & Sons. This book was released on 1982 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prestress Losses in Pretensioned High strength Concrete Bridge Girders written by Maher K. Tadros and published by Transportation Research Board. This book was released on 2003 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The HCM includes three printed volumes (Volumes 1-3) that can be purchased from the Transportation Research Board in print and electronic formats. Volume 4 is a free online resource that supports the rest of the manual. It includes: Supplemental chapters 25-38, providing additional details of the methodologies described in the Volume 1-3 chapters, example problems, and other resources; A technical reference library providing access to a significant portion of the research supporting HCM methods; Two applications guides demonstrating how the HCM can be applied to planning-level analysis and a variety of traffic operations applications; Interpretations, updates, and errata for the HCM (as they are developed);A discussion forum allowing HCM users to ask questions and collaborate on HCM-related matters; and Notifications of chapter updates, active discussions, and more via an optional e-mail notification feature."--Publisher.

Download or read book Guide for Concrete Slabs That Receive Moisture Sensitive Flooring Materials written by ACI Committee 302 and published by American Concrete Institute. This book was released on 2006 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integrated Materials and Construction Practices for Concrete Pavement written by and published by . This book was released on 2006 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Manual of integrated material and construction practices for concrete pavements.