Download or read book Development of Internally Cured Concrete for Increased Service Life written by John Schlitter and published by . This book was released on 2010-10-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Durable High Early Strength Concrete Via Internal Curing Approach Using Saturated Lightweight and Recycled Concrete Aggregates written by Faisal A. F. Qadri and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental exposure is one of the primary causes of concrete pavement deterioration, specifically cyclic freezing and thawing, as is common in Kansas. Rehabilitation of deteriorated concrete pavement is a common pavement life-extension strategy, and a variety of rehabilitation techniques are often utilized depending on the level of pavement distress. Budgetary constraints, however, often dictate use of partial and full-depth patching methods to rehabilitate deteriorated concrete pavement rather than replace an entire road. For roadways with high traffic volume, patching is often done overnight within few hours. These repairs include removing the old concrete and preparing the location for new concrete, which must achieve at least 1,800 psi compressive strength 6 hours prior to opening to traffic to avoid compromising future durability. Current patches last less than 10 years despite a nominal 20-year service life. This study utilized an internal curing technique to produce durable high early strength concrete for patching. Because desorbing water throughout the concrete matrix improves the microstructure and reduces porosity, lightweight aggregates and crushed concrete aggregates were each used to desorb water and provide internal curing. Tests were conducted to evaluate compressive strength, autogenous shrinkage, length change, and freezing and thawing related to mass change, length change, and relative dynamic modulus of elasticity (RDME). In contrast to ASTM C157, which only measures drying shrinkage after 14 days of curing, autogenous shrinkage of concrete was measured in this study. KTMR-22, developed by the Kansas Department of Transportation, was used to evaluate freeze-thaw durability of internally cured repair mixtures because this method subjects test specimens to a much harsher test regimen than ASTM C666. For example, KTMR-22 utilizes 660 cycles that simulate 20 years of exposure to 33 cycles of freezing and thawing compared to ASTM-666 exposure of only 300 cycles. Results showed that the mixture made with lightweight aggregate and low cement content met all requirements for expansion and RDME. This mixture also had minimum autogenous shrinkage among all the mixtures.
Download or read book Smart and Multifunctional Concrete Toward Sustainable Infrastructures written by Baoguo Han and published by Springer. This book was released on 2017-06-12 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest research advances and findings in the field of smart/multifunctional concretes, focusing on the principles, design and fabrication, test and characterization, performance and mechanism, and their applications in infrastructures. It also discusses future challenges in the development and application of smart/multifunctional concretes, providing useful theory, ideas and principles, as well as insights and practical guidance for developing sustainable infrastructures. It is a valuable resource for researchers, scientists and engineers in the field of civil-engineering materials and infrastructures.
Download or read book Cracking Control on Early Age Concrete Through Internal Curing written by Dejian Shen and published by Springer Nature. This book was released on 2023-07-10 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph is written based on the author's research on the assessment, control, and repair of cracking of early-age concrete in the recent decade. The technique of internal curing for increasing cracking resistance of early-age concrete is further developed through experimental and theoretical research. It establishes models for predicting the internal relative humidity and autogenous shrinkage of internally cured concrete at early age; reveals the variation law and mechanism of early-age tensile creep of internally cured concrete; and explores the variation law and mechanism of early-age cracking resistance of internally cured concrete under continuous restrained condition or uniaxial restrained condition. It is designed as a reference work for professionals or practitioners and a textbook for undergraduates or postgraduates. As such, this book provides valuable knowledge, useful methods, and practical experience that can be considered in the field of concrete cracking control.
Download or read book Behavior of Bridge with Internally Cured Concrete Deck Under Environmental and Truck Loading written by Waleed Khalid Hamid and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The long-term performance of a bridge deck depends on its resistance to bridge cracking. Most of these cracks are initiated at the early age. Early age cracking of bridge decks is a typical issue in the U.S. that reduces bridge service life. Therefore, internally cured concrete (ICC) has been used in some states to reduce or eliminate the development of cracks in reinforced concrete decks. In this study, the early age behavior of ICC deck and the effect of the internal curing on the long-term behavior of the bridge was measured and evaluated in the laboratory and field for newly adjacent constructed bridge, which were located on Route 271 in Mayfield, Ohio. Two different types of concrete mixtures were utilized for the decks: conventional concrete (CC) and internally cured concrete (ICC). Firstly, the ICC and CC mixtures were examined in the laboratory in terms of a mechanical properties test, a plastic shrinkage test, a free shrinkage test, and a restrained shrinkage test. Second, the field behavior of an ICC deck and an adjacent CC deck during their early age and long-term performance were evaluated. Also, the shrinkage development for both decks was examined during the very early age. Instrumentation was used to measure the concrete and reinforcement strains and the temperature in both bridges. The instrumentation and results for both bridges are discussed. Laboratory results indicated that using pre-wetted lightweight concrete in the concrete mixture led to decreased density, coefficient of thermal expansion, and free shrinkage strain, and increased tensile strength and cracking time of concrete compared to conventional concrete. In the field, from the early age test, it was observed that the time to develop concrete shrinkage was approximately 5-6 hours after casting the deck of the ICC and the CC.
Download or read book Internal Curing of Concrete written by Kyllastinen Karri and published by LAP Lambert Academic Publishing. This book was released on 2015-06-15 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internal curing was used already in the Roman times, for example the famous Pantheon building is done partly with internally cured concrete. The external curing of concrete such as fogging the surface only achieves the surface of the concrete, with internal curing the whole 3-dimensional microstructure of the concrete could be cured. The objective of this thesis was to study the impact of internal curing on compressive strength, tensile/flexural strength and drying shrinkage. The goal was also to determine which grain sizes lightweight aggregates will be the best in internal curing use. In this thesis the internal curing is done with lightweight aggregates. The obtained tests results showed that the best grain size of lightweight aggregates for internal curing are 0-2 mm and 2-4 mm. The usage of these sizes enabled to produce concrete having similar mechanical properties to normal concretes but significantly reduced drying shrinkage.
Download or read book Evaluation of Portland Cement Concrete with Internal Curing Capabilities written by John Kevern and published by . This book was released on 2016 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report 41 Internal Curing of Concrete State of the Art Report of RILEM Technical Committee 196 ICC written by Ole Mejlhede Jensen and published by RILEM Publications. This book was released on 2007 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International RILEM Conference on Early Age and Long Term Cracking in RC Structures written by Fragkoulis Kanavaris and published by Springer Nature. This book was released on 2021-05-18 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume gathers the latest advances, innovations and applications in the field of crack control in concrete, as presented by leading international researchers and engineers at the International RILEM Conference on Early-age and Long-term Cracking in RC Structures (CRC 2021), held in Paris, France on April 9, 2021. It covers early-age and long-term imposed deformations in concrete, analytical formulations for calculating crack widths in concrete, numerical simulations of early-age and long-term restrained behaviour of concrete elements, experimental investigations on cracking, on-site monitoring of imposed deformations and cracking, crack control and repair, and sustainability of design and remediation. The conference demonstrated that a comprehensive approach to this problem requires the design of robust experimental techniques, the development of multiscale models and the evaluation of code-based and other analytical approaches relevant to crack control in concrete. The contributions, which were selected through a rigorous international peer-review process, share exciting ideas that will spur novel research directions and foster new multidisciplinary collaborations.
Download or read book Moisture Transport in Cement Based Materials written by Javier Eduardo Castro and published by . This book was released on 2011 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: The durability of concrete subjected to aggressive environments depends largely on the transport properties of the concrete. These transport properties are influenced by the volume of pores as well as the connectivity of the pore network. Three main mechanisms can be used to describe transport in cementitious systems: permeability, diffusion and absorption. Permeability is the measure of the flow of water under a pressure gradient. Diffusion is the movement of ions due to a concentration gradient. Absorption can be described as the ability to take in water by means of capillary suction. It is important to note that absorption occurs on a much faster time scale than diffusion. A large fraction of concrete in service is only partly saturated and the initial ingress of fluid is influenced, at least in part, by capillary absorption. As such, fluid (water) absorption has been used as an important factor for quantifying the durability of cementitious systems and it is being increasingly used by specifiers and in forensic studies to provide a parameter that can describe an aspect of concrete durability. For this reason the water absorption test is the focus of the first part of this thesis. The influence of preconditioning and initial moisture content was assessed as it relates to the water absorption test measurements. The results confirm that the test is considerably affected by the relative humidity of the samples before starting the test, which if not properly accounted for can lead to a misunderstanding of the actual absorption behavior. It was also observed that the conditioning procedure described in ASTM C1585 is not able to eliminate the "moisture history" of the samples. As such modifications to the standard test procedure are suggested. Further, the absorption behavior was investigated when salts were present in the samples or as a part of the absorbing fluid. Tests were performed on concrete using different aqueous solutions containing deicing salts. The rate of fluid absorption was generally lower for aqueous solutions containing deicing salts than it was for water (with the exception of low concentrations of NaCl). The change in the rate of aqueous fluid absorption was proportional to the square root of the ratio of surface tension and viscosity of the absorbed fluid. Experimental data indicates that concretes that had previously been exposed to deicing solutions can also exhibit reduced rate of absorption, even if water is the fluid being absorbed. The second part of this thesis is focused on the internal curing for concrete and its effect on the transport properties. The increased propensity for shrinkage cracking in low waterto- cement ratio (w/c) concrete has inspired the development of new technologies that can reduce the risk of early-age cracking. One of these is internal curing. Internal curing uses pre-wetted lightweight aggregate (LWA) to supply "curing water" to low w/c paste as it hydrates. Significant research has been performed to determine the effects of internal curing on shrinkage and stress development; however, relatively little detailed information exists about the effects of internal curing on fluid transport properties such as water absorption. In order to determine the mixture proportions for internally cured concretes information about the water absorption and water desorption properties of the lightweight aggregate is needed. Unfortunately, these properties are not easy to obtain accurately. This work studies the absorption and desorption properties of commercially available expanded shale, clay and slate lightweight aggregates. This research determines these properties so that they can be efficiently used in proportioning concrete for internal curing. Further, it was shown that by normalizing the results general trends on material behavior can be obtained that are quite useful in proportioning the mixtures. After characterizing the properties of the aggregates to be used for internal curing, this research examines the absorption of water into low w/c mortar specimens made with prewetted lightweight aggregates. These results indicate that the inclusion of LWA can reduce the water absorption of mortar specimens. This observation was reinforced with electrical conductivity measurements that exhibited similar reductions. In addition, this work analyzes the potential use of internal curing in concrete systems with w/c higher than normally used (w/c of 0.30, 0.36, 0.42 and 0.45) to increase the durability of the concrete. Test results show that internal curing can be useful to improve the durability of concretes prepared with this wider range of w/c. The benefits of using internal curing on the transport properties can be explained by an increase in the hydration of the cement. This was assessed using isothermal calorimeter, internal relative humidity, scanning electron microscopy and an atomic force microscopy. Further, in addition to reducing the porosity, the increased hydration appears to reduce the tortuosity by preferentially hydrating the interfacial regions around the lightweight aggregate.
Download or read book Internal Curing of High Performance Concrete Using Lightweight Aggregates and Other Techniques written by and published by . This book was released on 2014 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internally cured concrete has been rapidly emerging over the last decade as an effective way to improve the performance of concrete. Internal curing (IC) holds promise for producing concrete with an increased resistance to early-age cracking and enhanced durability. It is a simple and effective way to cure concrete.
Download or read book Durability of Internally Cured Concrete with Reclaimed Sands written by Kienan Dalesandro and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A significant portion of municipal solid waste has traditionally been addressed through recycling; however, the recycling market has become unreliable due to the stringent contamination regulations imposed by Chinas new recycling policy. Solid waste can be addressed through incineration which reduces the volume of the waste. Waste-to-Energy facilities provide an efficient means to carry out the incineration process by generating electricity through steam generation. Although it is not completely waste free, this process leaves a by-product known as municipal solid waste incinerator ash that can be further refined into a lightweight sand material known as reclaimed sands. This work investigates the use of reclaimed sands from the York County Solid Waste Authority in York, PA as a partial replacement for fine aggregates to make internally cured concrete. In internally cured concrete, interior particles release water during the cement hydration process and effectively help the mix cure from the inside out. This leads to a less permeable concrete that increases the freeze-thaw resistance, reduces chloride permeability, and improves the shrinkage resistance of the material. Reclaimed sands are effective internal curing aggregates, since they have a high absorption capacity and the ability to desorb water at a high relative humidity. The testing performed in this work explores the durability of internally cured concrete manufactured with reclaimed sands by assessing the freeze thaw resistance, rapid chloride permeability, and compressive strength of the concrete. As is discussed in later chapters of this work, it was found that reclaimed sands are a suitable replacement for lightweight aggregate in internal curing concrete applications.
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 Early age Cracking Control on Modern Concrete written by Dejian Shen and published by Springer Nature. This book was released on with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impacts of Internal Curing on Concrete Properties written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional concrete is typically cured using external methods. External curing prevents drying of the surface, allows the mixture to stay warm and moist, and results in continued cement hydration (Taylor 2014). Internal curing is a relatively recent technique that has been developed to prolong cement hydration by providing internal water reservoirs in a concrete mixture that do not adversely affect the concrete mixture's fresh or hardened physical properties. Internal curing grew out of the need for more durable structural concretes that were resistant to shrinkage cracking. Joint spacing for concrete overlays can be increased if slab warping is reduced or eliminated. One of the most promising potential benefits from using internal curing for concrete overlays, then, is the reduced number of joints due to increased joint spacing (Wei and Hansen 2008).
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 Internal Curing of High performance Concretes written by D. Bentz and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
