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 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 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 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 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 An Introduction to Internal Curing of Concrete Pavement written by J. Paul Guyer, P.E., R.A. and published by Guyer Partners. This book was released on 2019-08-14 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introductory technical guidance for civil engineers and construction managers interested in internal curing of portland cement concrete pavement. Here is what is discussed: 1. INTRODUCTION 2. PAVEMENT APPLICATIONS 3. MIXTURE DESIGN FOR INTERNAL CURING 4. CONCRETE PAVEMENT CONSTRUCTION ASPECTS OF INTERNALLY CURED CONCRETE 5. PROPERTIES OF INTERNALLY CURED CONCRETE 6. PRACTICAL APPLICATIONS 7. SUMMARY 8. REFERENCES.

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 215 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 Effects of Internal Curing Methods on Restrained Shrinkage and Permeability written by Hoa Lam and published by . This book was released on 2005 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this thesis is to investigate the ability of internal curing methods including superabsorbent polymers (SAP) and saturated lightweight aggregate to mitigate autogenous shrinkage and restrained shrinkage. This thesis also examines the changes in properties of concrete and mortar, such as permeability, when SAP, lightweight aggregate or shrinkage reducing admixtures (SRA) are introduced to the mix. This research found that mortar containing SAP was able to minimize the amount of autogenous shrinkage, but reduced the compressive strength considerably, similar to air-entraining concrete. SAP was also able to leave voids in the concrete, which simulate normal entrained air. SRA was most effective at reducing drying shrinkage. Lightweight aggregate has an interlocking bond with the paste at the interfacial transition zone; thus increased its tensile strength properties.

Download or read book Effects of Internal Curing Methods on Restrained Shrinkage and Permeability microform written by Hoa Lam and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2005 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this thesis is to investigate the ability of internal curing methods including superabsorbent polymers (SAP) and saturated lightweight aggregate to mitigate autogenous shrinkage and restrained shrinkage. This thesis also examines the changes in properties of concrete and mortar, such as permeability, when SAP, lightweight aggregate or shrinkage reducing admixtures (SRA) are introduced to the mix. This research found that mortar containing SAP was able to minimize the amount of autogenous shrinkage, but reduced the compressive strength considerably, similar to air-entraining concrete. SAP was also able to leave voids in the concrete, which simulate normal entrained air. SRA was most effective at reducing drying shrinkage. Lightweight aggregate has an interlocking bond with the paste at the interfacial transition zone; thus incresed its tensile strength properties.

Download or read book Guide for Modeling and Calculating Shrinkage and Creep in Hardened Concrete written by and published by . This book was released on 2008-01-01 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Mechanical Engineering written by Gaurav Manik and published by Springer Nature. This book was released on 2021-06-26 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of Congress on Advances in Materials Science and Engineering (CAMSE 2020). It focuses on the state-of-the-art research, development, and commercial prospective of recent advances in mechanical engineering. The book covers various synthesis and fabrication routes of functional and smart materials for applications in mechanical engineering, manufacturing, physics, chemical and biological sciences, metrology, optimization and artificial intelligence among others. This book will be a useful resource for researchers, academicians as well as professionals interested in the highly interdisciplinary field of materials science and mechanical engineering.

Download or read book Improving Service Life of Concrete Structures Through the Use of Internal Curing written by Timothy J. Barrett and published by . This book was released on 2015 with total page 483 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Indiana Department of Transportation (INDOT) commissioned the construction of six bridge decks utilizing a new class of internally cured high performance concrete (IC HPC). The first four bridge decks were constructed in the summer of 2013, while the fifth was built in November of 2014 and the sixth is planned for the summer of 2015. These decks implement research findings presented in the FHWA/IN/JTRP-2010/10 report (Schlitter, Henkensiefken, et al. 2010) where internal curing was proposed as one method to reduce the potential for shrinkage cracking, leading to improved durability. In addition, the use of higher performance concrete mixtures and a new specification composed of prescriptive and performance based measures was implemented with the intention of extending the service life of the bridge decks. The objectives of this thesis are to provide documentation of the construction and performance of the IC HPC bridge decks cast in Indiana and provide a viable, practice-ready method for the assessment of the potential durability of these concretes. In fulfillment of these objectives, samples of the IC HPC used in construction were compared to a reference high performance concrete (HPC) which did not utilize internal curing and was made by the same producer with the same constituent materials. The samples collected in the field were transported to the laboratory where the mechanical performance, resistance to chloride ingress, and potential for shrinkage and cracking was assessed. Using experimental results and mixture proportions, the diffusion based service life of the bridge decks was able to be estimated. The construction process was documented for first four bridge decks made using internal cured high performance concrete (IC HPC). These concretes were able to be designed, batched, and placed and are now in service. While avoidable issues were observed during batching construction related to corrections of batching water, batching tolerances and fluctuations in air content (which apply to any concrete), the IC HPC was able to be batched and placed using slight modifications to conventional methods. The production of the IC HPC mixtures was implemented using a mixed specification using prescriptive and performance based measures representing an improvement on previous specifications which did not specifically have provisions that consider durability. To aid in the implementation of internal curing in the field, a new quality control technique for lightweight aggregate utilizing a centrifuge has been implemented is now standardized in Indiana Testing Method 222 (Miller, Barrett, et al. 2014). The results of laboratory testing indicate that the compressive strength, modulus of elasticity, and tensile strength of the IC HPC mixtures was not substantially different than the HPC mixtures and as such current codified equations are able to be used to predict the modulus of elasticity and tensile strength if the compressive strength is known. The diffusion of chlorides in these concretes was assessed, where it was shown that each of the mixtures tested had a charge passed in the rapid chloride permeability test of less than 1500 C at 91 days (AASHTO T277-07 2007); additional testing provided equivalent results when performing the Nordtest (NT Build 492 1999), Stadium migration test , or electrical resistivity test. Using experimental results which determined the chloride diffusion and permeability, the diffusion based service life of the IC HPC bridge decks was estimated to be between approximately 60 to 90 years, compared to approximately 18 years for the conventional class C bridge deck concrete used in Indiana. The susceptibility to early age shrinkage and cracking was evaluated where it was shown that IC HPC concretes exhibited a reduction in early age shrinkage of 70 to 90%, resulting in a reduction in residual stresses of 80% or more while reducing thermally induced stress by up to 55% when compared to HPC mixtures. Collectively, these results indicate that the IC HPC mixtures that were produced as a part of this study exhibit the potential of for substantially increased service life while markedly reducing the potential for early age cracking. The second phase of this thesis investigated the role of initial sample conditioning and the effect of changes in degree of saturation on the measured electrical resistivity, where a new function was developed to describe this relationship in air entrained concretes. The consistency and variability in the determination of the chloride diffusion coefficient was investigated through standardized testing methods, where it was shown that the coefficient of variation associated with the accelerated tests was approximately 15% or less and are dependent on the test. Chloride profile measurements made on cores taken from samples which were exposed with a known deicing solution and the temperature fluctuations of West Lafayette, Indiana indicated that on average, the coefficient of variation for determining the apparent chloride diffusion coefficient under is 30% or less. In addition, the use of resistivity measurements on sealed samples was used to evaluate the variability of the concrete produced throughout the construction of the fifth IC HPC bridge deck while comparisons of the samples from the first four bridge decks produced in the laboratory and in the field were also made. The results indicated that the coefficient of variation associated with the resistivity measurements made on the fifth bridge deck was less than 5%, while experimental results indicated that industrial production consistently results in lower performance as measured by the resistivity test when compared to laboratory production. In this study it was also shown that measurements of mechanical properties are not indicative of the potential durability of the concrete. The conclusions of this thesis and the findings presented in the FHWA/IN/JTRP-2010/10 report (Schlitter, Henkensiefken, et al. 2010) and the CDOT-2014-3 report (Jones et al. 2014) indicate that internal curing is a practice-ready, engineered solution that may lead to the production of higher performance concretes which have a reduced potential for cracking. To aid in the implementation of internal curing in practice, spreadsheets which automate calculations necessary for quality control for lightweight aggregates, mixture proportioning, and moisture adjustments have been developed by Miller (2014) and have been made available with the report documenting the construction of the first four bridge decks (Barrett et al. 2015). This thesis also provided the framework for a durability based design approach using sealed electrical resistivity measurements which may be implemented in practice. This method has been shown to be a viable way to rapidly evaluate the chloride diffusion coefficient of concrete and is appropriate for testing large numbers of samples during construction. It is recommended that the approach outlined in this work be implemented in performance based specifications in lieu of other accelerated testing methods which define the performance of the concrete based on the result of that test. Finally, it should be emphasized that the implementation of technologies such as those that are presented in this thesis alone does not guarantee higher performance, as the production of such concrete requires a degree of technical competence in design, production, and construction of concrete materials. As is the case with the production of any concrete, internally cured or not, performance will be directly tied to the careful accounting of water, be it on the surface of aggregates, in the mixing drum after washing, or elsewhere. Special attention should be paid to the proper operation of batching systems, while placement techniques should be reviewed to minimize unwanted effects, and proper finishing and curing techniques must always be practiced. Only after performing the basics of concrete production properly will the full benefits of internal curing be actualized.

Download or read book Design and Control of Concrete Mixtures written by Steven H. Kosmatka and published by . This book was released on 1988 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Portland Cement Association reference, dealing with fundamentals, cold weather concreting, curing, admixtures, aggregates, mixing, and much more.

Download or read book Effect of Internal Curing on Freeze Thaw Durability of Dry Cast Concrete Segmental Retaining Wall Units and Solid Interlocking Concrete Paving Units written by Craig Walloch and published by . This book was released on 2014 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dry-cast concrete segmental retaining wall (SRW) units and solid interlocking concrete paving units are governed by ASTM C1372 [Standard Specification for Dry-Cast Segmental Retaining Wall Units, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2011] and ASTM C936/C936M [Standard Specification for Solid Concrete Interlocking Paving Units, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2011], respectively. Resistance to freeze-thaw damage is an important performance criterion for these products. These units are produced on machines using vibration-compacted zero-slump concrete. The combination of low water-cement ratio, well-graded aggregates, and intense compaction results in dense, high-strength units without the entrained air necessary in wet-cast concrete to improve freeze-thaw durability. The high-cement content, low-water-cement ratio and short curing time result in a significant percentage of the cement remaining unhydrated. Internal curing (IC) through the use of pre-soaked lightweight aggregates that act as long-term water reservoirs during the cement hydration process is a proven technology that has been optimized in wet-cast concrete to increase the degree of cement hydration and improve durability. For this study, pre-soaked lightweight aggregates were incorporated into SRW units and concrete pavers in an attempt to increase the degree of cement hydration, thereby increasing the quality of the cement paste and improving the freeze-thaw durability of the units. Internally cured SRW units were subjected to ASTM C1262-10 [Standard Test Method for Evaluating the Freeze-Thaw Durability of Dry-Cast Segmental Retaining Wall Units and Related Concrete Units, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2010] freeze-thaw testing. Internally cured concrete pavers were subjected to ASTM C1645-11 [Standard Test Method for Freeze-Thaw and De-Icing Salt Durability of Solid Concrete Interlocking Paving Units, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2011] and CSA A231.2-06 ["Precast Concrete Pavers," Canadian Standards Association, Mississauga, Ontario, Canada, 2006] freeze-thaw testing in 3 % saline solution, as well as ASTM C418 [Standard Test Method for Abrasion Resistance of Concrete by Sandblasting, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2005] abrasion-resistance testing. The results demonstrate a definite improvement in durability properties of the pavers when internal curing is utilized. In addition, petrographic and scanning electron microscopy studies of the concrete pavers document a significant increase in the degree of cement hydration and quality of the cement paste that is achieved with internal curing. Results of the freeze-thaw tests on SRW units were not conclusive with regard to the effects of internal curing. The petrographic studies of the SRW units showed non-uniform improvement in the degree of cement hydration.

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 Curing Concrete written by Peter C. Taylor and published by CRC Press. This book was released on 2013-09-10 with total page 220 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 mean that they are less forgiving than in the past. Therefore, any activity that will help improve hydration and so performance, while reducing the risk of cracking, is becoming more important. Curing Concrete explains exactly why curing is so important and shows you how to best do it. The book covers: The fundamentals behind hydration How curing affects the properties of concrete, improving its long-term performance What curing technologies and techniques you can use for different applications How to effectively specify, provide, and measure curing in a project The author also gives numerous examples of how curing—or a lack of it—has affected concrete performance in real-world situations. These include examples from hot and cold climates, as well as examples related to high-performance concrete, performance parameters, and specifications and testing. Written for construction professionals who want to ensure the quality and longevity of their concrete structures, this book demonstrates that curing is well worth the effort and cost.

Download or read book Measuring Monitoring and Modeling Concrete Properties written by Maria S. Konsta-Gdoutos and published by Springer Science & Business Media. This book was released on 2007-09-23 with total page 761 pages. Available in PDF, EPUB and Kindle. Book excerpt: This state-of-the-art volume covers the latest and future trends in measuring, monitoring and modeling the properties of cement based materials. The book contains 94 papers and presents the latest research work of renowned experts. It acts as a survey of the most up-to-date research in the field.