Download or read book Investigation of the Effect of Sulfuric Acid Solution on the Properties of Both Plain and Air entrained Concrete written by and published by . This book was released on 1952 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laboratory Reports written by United States. Bureau of Reclamation. Technical Library, Denver and published by . This book was released on 1952 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to Laboratory and Other Numbered Reports written by Ferdinand Stenger and published by . This book was released on 1957 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dictionary Catalog of the Department Library written by United States. Department of the Interior. Library and published by . This book was released on 1967 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The National Union Catalog 1952 1955 Imprints written by and published by . This book was released on 1961 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The National Union Catalog Pre 1956 Imprints written by and published by . This book was released on 1975 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of the Effects of Air Entraining Agents Air Detraining Agents and Their Combinations on the Properties of Mortars and Cement Pastes written by A. M. Cooke and published by . This book was released on 1973 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book National Union Catalog written by and published by . This book was released on 1961 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes entries for maps and atlases.
Download or read book A Laboratory Investigation of the Effect of Pumping on Entrained Air Voids in Concrete written by William Elkey and published by . This book was released on 1995 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book HRIS Abstracts written by National Research Council (U.S.). Highway Research Information Service and published by . This book was released on 1988 with total page 930 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of a Proprietary Chemical Admixture on the Properties of Concrete written by Waterways Experiment Station (U.S.) and published by . This book was released on 1954 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of Concrete with Blended Binders in Sulfuric Acid and Ammonium Sulphate Solutions written by Mahmud Amin and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acid attacks on concrete impart unique set of damage mechanisms and manifestations compared to other durability issues of concrete. Up to date, there are still research gaps and conflicting data regarding the effects of supplementary cementitious materials (SCMs) at improving the resistance of concrete to acidic exposures. Hence, this thesis aims at understanding the role of SCMs in the performance of concrete under two different acidic environments (sulfuric acid and ammonium sulfate solutions) that produce similar reaction products while their damage mechanisms and manifestations are completely different. Concrete has long been the most popular choice for constructing key infrastructural elements such as sewer pipes, water treatment facilities, industrial floors and foundations, which can be chemically vulnerable to damage by sulfuric acid attack. Since high alkalinity is required for the stability of the cementitious matrix, concrete is susceptible to attack by acidic media, which may disintegrate the hydrated cement paste to various levels based on the prevailing exposure conditions and key mixture design parameters of concrete. The aim of this part of research was to investigate the response, in terms of phyico-mechanical and microstructural features, of concrete comprising different types of cement (general use or portland limestone cement [PLC]) with various combinations of SCMs (fly ash, silica fume and nano-silica) to a severe sulfuric acid exposure. The project comprised 13 weeks (90 days) of immersing test specimens in 5% sulfuric acid solutions with a maximum pH threshold of 2.0. The results revealed that the surface degradation (mass loss) of concrete under severe sulfuric acid attack was independent of its penetrability (physical resistance), since very dense cementitious matrices (low penetrability) suffered from severe deterioration. Portland limestone cement [PLC] may slightly improve the resistance of concrete to sulfuric acid attack, whereas among the blended binders tested, binary binders comprising 30% fly ash showed increased resistance of concrete to sulfuric acid attack due to an inert filler effect at the exposed surface. On the other hand, concrete elements in agricultural, wastewater treatment, mining and industrial applications can be vulnerable to chemical attack by ammonium-based solutions. In particular, ammonium sulfate (commonly used as a fertilizer) is extremely deleterious to concrete due to its dual acid-sulfate action, which may disintegrate the hydrated cement paste to various levels based on the prevailing exposure conditions and key mixture design parameters of concrete. The aim of the second part of research was to investigate the response, in terms of physico-mechanical and microstructural features, of concrete comprising different types of cement (general use or PLC) with various combinations of SCMs (fly ash, silica fume and nano-silica) to a severe ammonium sulfate exposure. This part comprised 12 months of immersing test specimens in 5% ammonium sulfate solutions with a pH level of 6.0-8.0. The results revealed that the type of binder along with the dosage and nature of SCMs dictated different modes and levels of deterioration, and in turn physico-mechanical trends of concrete characterised by softening with (single binders) or without (blended binders) significant expansion. PLC may slightly improve the resistance of concrete to ammonium attack, whereas among the blended binders tested, binary binders comprising 5% silica fume, 5% nano-silica, or 30% fly ash particularly improved the resistance of concrete to this type of chemical attack.
Download or read book Concrete Abstracts written by and published by . This book was released on 1987 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Properties of Air Bubbles in Air Entrained Concrete written by Le Tuan Pham and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is widely accepted that air entrainment, a purposeful introduction of small air bubbles in concrete, is critical to the long-term durability of concrete in freeze-thaw environments. Air entraining admixtures (AEA) are added to the mixture to stabilize air bubbles created during mixing, ensuring a proper air void system in the hardened concrete. Despite the complexity of creating a suitable air void system in concrete, previous study and experience established the reliability and robustness of such systems under a variety of conditions through use of neutralized vinsol resin (NVR) AEA products. In recent years, synthetic AEAs have been used more frequently due to limited supply of NVR to the concrete industry. With the use of synthetic AEAs, there are more reports of new problems including difficulties in accurately measuring the air content. This study was conducted to find the root cause of the increasing difficulties in controlling the air contents in portland cement concrete associated with synthetic AEAs. Main challenges included the lack of existing techniques to evaluate AEAs and air bubbles in concrete, and lack of data to help identify causes. Given these challenges, a multi-scale experimental study that included testing of field and laboratory concrete, and testing of foam and individual air bubbles was undertaken. The results indicate that the disparity between QC test results and the actual air contents in concrete pavements associated with the use of synthetic AEAs could be attributed to less robust air bubbles stabilized with synthetic AEAs compared to those entrained with NVR and the resulting increased loss of these air bubbles during concrete sampling. The cause of this decreased robustness and resulting air loss was traced directly to the properties of the bubble shells. The shells of air bubbles in concrete entrained with synthetic AEAs were thinner and less stiff than those associated with an NVR AEA. Through this research new test protocols were developed to measure stiffness and thickness of the shell of air bubbles extracted from cement paste and to quantify stability of foams of AEAs in a cementitious environment. These tests could be used by researchers and practitioners who are interested in developing new admixtures and/or identifying admixtures with undesirable performance.
Download or read book Investigation of the Cause and Effect of Air Void Coalescence on Air Entrained Concrete Mixes written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Air entraining admixtures (vinsol or non-vinsol) are used in concrete mixes that will be exposed to freeze-thaw cycles or sulfate attack. Entrained air is intended to improve the durability and resistance of hardened concrete to freeze-thaw cycles. However in many instances a significant loss of compressive strength has been observed in concrete mixes containing non-vinsol admixtures. Mixture forensic analysis has determined air void coalescing to be the main factor in observed low compressive strengths. The result of air void coalescing is the over design of compressive strength to account for the possible lower strengths and decreased confidence in the compressive strengths obtained during the quality control/assurance process.
Download or read book Investigation of the Effect of Vibration Time on the Bleeding Property of Concrete with and Without Entrained Air written by R. J. Elfert and published by . This book was released on 1948 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Loss of Entrained Air in Freshly Mixed Concrete and the Effect of this Loss on the Properties of the Hardened Concrete written by H. L. Flack and published by . This book was released on 1949 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
