The Experts below are selected from a list of 24822 Experts worldwide ranked by ideXlab platform
Zhang Tao - One of the best experts on this subject based on the ideXlab platform.
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Experimental Research on Compressive Strength of Waste Incineration Bottom Ash Concrete
Bulletin of the Chinese ceramic society, 2010Co-Authors: Zhang TaoAbstract:The bottom Ash was used as Concrete coarse aggregate and study the failure mode of waste incineration bottom Ash Concrete,the relationship between compressive strength and bottom Ash coarse aggregate replacement rate,water cement ratio,apparent density and development trend of compressive strength were studied.The failure mode of waste incineration bottom Ash Concrete is similar to normal Concrete and acicular content has effect on compressive strength.Bottom Ash coarse aggregate replacement rate has different effects on compressive strength in different water cement ratio.Compressive strength of waste incineration bottom Ash Concrete has the same development trend with normal Concrete.Compressive strength and apparent density has a linear relation.We can produce economical C20,C25 and C30 Concrete by choosing the best bottom Ash coarse aggregate replacement rate and water cement ratio.
Nabil M. Al-akhras - One of the best experts on this subject based on the ideXlab platform.
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Durability of wheat straw Ash Concrete to alkali-silica reaction
Proceedings of the Institution of Civil Engineers - Construction Materials, 2013Co-Authors: Nabil M. Al-akhrasAbstract:This study investigated the effect of wheat straw Ash on the durability of Concrete to detrimental alkali-silica reaction. Three wheat straw Ash levels were considered in the study: 5, 10 and 15% as a partial replacement of cement. The other experimental parameters investigated in the study were: w/b ratio (0·5 and 0·6) and initial curing type (moist and autoclaving). Crushed Pyrex glass was used as reactive fine aggregate in the study. After the initial curing, the Concrete specimens were immersed in a 1 N NaOH solution tank at 40°C to accelerate the deleterious alkali-silica reaction. The alkali-silica reaction deterioration was assessed by measuring the expansion of Concrete prisms and the reduction in compressive strength. The study showed that the wheat straw Ash Concrete was more durable to alkali-silica reaction damage than the control Concrete. The durability of wheat straw Ash Concrete increased with increasing the wheat straw Ash content. The wheat straw Ash Concrete with w/b ratio of 0·5 showed...
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Durability of wheat straw Ash Concrete exposed to freeze–thaw damage
Proceedings of the Institution of Civil Engineers - Construction Materials, 2011Co-Authors: Nabil M. Al-akhrasAbstract:This study investigated the effect of wheat straw Ash on the durability of Concrete to freeze–thaw deterioration. Three wheat straw Ash replacement levels were considered in the study: 5, 10 and 15% by weight of cement. The other experimental parameters investigated in the study included: aggregate type (basalt and pumice), water/binder ratio (0·5 and 0·7) and maximum aggregate size (9·5 and 19 mm). After the initial moist curing, wheat straw Ash Concrete prisms were subjected to accelerated freeze–thaw cycles following ASTM Procedure B (rapid freezing in air and thawing in water). The freeze–thaw deterioration of wheat straw Ash Concrete specimens was evaluated using the relative dynamic modulus of elasticity and durability factor. The results showed that the durability of wheat straw Ash Concrete to freeze–thaw deterioration was greater than that of plain Concrete. Furthermore, the durability of wheat straw Ash Concrete to freeze–thaw deterioration increased with increasing wheat straw Ash replacement l...
Vinita Vishwakarma - One of the best experts on this subject based on the ideXlab platform.
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Study on polymeric coatings on fly Ash Concrete under seawater.
Environmental science and pollution research international, 2020Co-Authors: Roselin Sobha Joseph Boopaphi, Ramachandran Dasnamoorthy, Manoj Kumaar Chandrasekaran, Vinita VishwakarmaAbstract:This study is focused on polymeric coatings on fly Ash Concrete submerged under seawater. The specimens were casted and coated with acrylic resin and epoxy resin of three layers each. The mechanical, durability, and microstructural properties of coated and uncoated fly Ash Concrete specimen were studied as pre- and post-exposed in seawater. Fly Ash Concrete coated with epoxy and acrylic had attained more strength compared to uncoated specimens. An increased strength in coated specimens and a decrease in value were observed in uncoated fly Ash Concrete specimens during split tensile strength. Coated specimens showed less reduction in pH value as compared to uncoated specimens. Rapid chloride permeability test (RCPT) analysis confirmed that epoxy and acrylic-coated Concrete specimens appear to be denser than uncoated specimens leading to more resistance against the penetration of aggressive chemicals. The X-ray diffraction (XRD) comparative analysis of 56 and 90 days acrylic resin and epoxy resin-coated and uncoated specimen showed higher intensity in 90 days coated specimens than the uncoated specimens. Field emission scanning electron microscope (FESEM) investigation of uncoated 56 and 90 days Concrete specimens subjected to seawater demonstrated dense appearance of hydrated products, whereas epoxy and acrylic-coated specimens were verified with no visible micro-cracks or holes on the surface, even at higher magnification. The epoxy and acrylic-coated fly Ash Concrete showed high physical strength and good bonding with Concrete and will be appropriate for construction.
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Studies of carbonation process in nanoparticles modified fly Ash Concrete
Construction and Building Materials, 2020Co-Authors: D. Ramachandran, Sudha Uthaman, Vinita VishwakarmaAbstract:Abstract The major cause of Concrete corrosion is carbonation where atmospheric carbon dioxide (CO2 penetrates the Concrete structure and deteriorates it. In this study, fly Ash Concrete (FA) with 40 percentage by weight (wt.) of cement, 2 wt% of TiO2 nanoparticles added to fly Ash Concrete (FAT), 2 wt% of CaCO3 nanoparticles added to fly Ash Concrete (FAC) and equal ratio (1:1) of CaCO3 and TiO2 nanoparticles was added to fly Ash Concrete with (FATC). After curing, these specimens were exposed in atmospheric condition, accelerated carbonation and sea water for 56 and 90 days and withdrawn for various analyses. TGA/DTA was done before exposing the specimens in different environments. The post-exposure analysis included surface pH, carbonation depth and XRD and FESEM to analyses the crystalline phases and morphology of specimens. Results showed that FA Concrete modified with nanoparticles has decreased the carbonation depth. Among different types of FA Concrete, FATC with an equal ratio of CaCO3 and TiO2 nanoparticles showed higher carbonation resistance in all environments.
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Enhanced seawater corrosion resistance of reinforcement in nanophase modified fly Ash Concrete
Construction and Building Materials, 2019Co-Authors: Sudha Uthaman, R. P. George, Vinita Vishwakarma, Manu Harilal, John PhilipAbstract:Abstract This paper presents a method for enhancing the corrosion resistance of reinforcements through nanophase modification of fly Ash Concrete. A combination of natural and accelerated corrosion tests were performed to evaluate the corrosion resistance of reinforcements. The tests were conducted on four types of fly Ash Concrete specimens with and without nanoparticles designated as fly Ash Concrete with 40 wt% fly Ash (FA), fly Ash Concrete with 2 wt% nano-CaCO3 (FAC), fly Ash Concrete with 2 wt% nano-TiO2 (FAT) and fly Ash Concrete with 1 wt% nano-CaCO3 and 1 wt% nano-TiO2 (FATC). Electrochemical measurements showed that reinforcements in nano-CaCO3 modified fly Ash Concrete (FAC) exhibited noble potential value, high polarization resistance and lower corrosion rate. Impressed voltage test also corroborate the enhanced corrosion resistance of FAC specimens, which was evident from the longer crack initiation time with minimum anodic current as compared to fly Ash Concrete without nano additives. Corrosion products of cover Concrete showed a comparatively lesser amount of detrimental phases like lepidocrocite and goethite which was in agreement with the corrosion results. The least depth of chloride ion penetration indicated the effective plugging of pores by nano-CaCO3 particles that prevent diffusion and movement of chloride ions to surface of the rebar and thereby maintaining the passivity of the thin iron oxide layer around the steel rebar.
Okan Karahan - One of the best experts on this subject based on the ideXlab platform.
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properties of steel fiber reinforced fly Ash Concrete
Construction and Building Materials, 2009Co-Authors: Cengiz Duran Atis, Okan KarahanAbstract:Abstract This paper reports on a comprehensive study on the properties of Concrete containing fly Ash and steel fibers. Properties studied include unit weight and workability of fresh Concrete, and compressive strength, flexural tensile strength, splitting tensile strength, elasticity modulus, sorptivity coefficient, drying shrinkage and freeze–thaw resistance of hardened Concrete. Fly Ash content used was 0%, 15% and 30% in mass basis, and fiber volume fraction was 0%, 0.25%, 0.5%, 1.0% and 1.5% in volume basis. The laboratory results showed that steel fiber addition, either into Portland cement Concrete or fly Ash Concrete, improve the tensile strength properties, drying shrinkage and freeze–thaw resistance. However, it reduced workability and increase sorptivity coefficient. Although fly Ash replacement reduce strength properties, it improves workability, reduces drying shrinkage and increases freeze–thaw resistance of steel fiber reinforced Concrete. The performed experiments show that the behaviour of fly Ash Concrete is similar to that of Portland cement Concrete when fly Ash is added.
Isamu Yoshitake - One of the best experts on this subject based on the ideXlab platform.
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Uniaxial tensile strength and tensile Young’s modulus of fly-Ash Concrete at early age
Construction and Building Materials, 2013Co-Authors: Isamu Yoshitake, Wenbo Zhang, Yoichi Mimura, Tadashi SaitoAbstract:Abstract The present study investigates the tensile strength and Young’s modulus of fly-Ash Concrete at early age by using a prismatic specimen with an embedded reinforcing bar. Tests were conducted on both normal Concrete and fly-Ash Concrete with a cement-replacement ratio of 20%. Three fly-Ash Concretes were placed and cured in field environmental conditions in summer, autumn and winter in western Japan. The tension test was performed to quantify the uniaxial tensile strength and tensile Young’s modulus of such fly-Ash Concrete at early age. Based on the test results, the paper presents empirical formulae for both strength and Young’s modulus.
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Strength Properties of Fly-Ash Concrete Placed and Cured in the Field
Journal of the Society of Materials Science Japan, 2012Co-Authors: Wenbo Zhang, Isamu Yoshitake, Eri Ogami, Yoichi Mimura, Tadashi SaitohAbstract:This paper presents compressive and tensile strengths of fly-Ash Concrete, which is classified as type II in the JIS. Fly-Ash Concretes were made in different seasons, including summer, autumn and winter. The Concretes were made in a ready-mixed Concrete plant and were cured in the field to simulate actual construction conditions. To investigate fundamental mechanical properties of the fly-Ash Concretes, strength tests were conducted at several ages. The paper gives the results of compressive strength, splitting tensile strength and uniaxial tensile strength tests. The study uses the Goral curve for the regression of compressive strength developed with an equivalent age based on the maturity. In the regression result, the coefficient of the Goral curve develops with lower temperatures. The results imply that evaluations using the equivalent age are not always appropriate for predicting the compressive strength of fly-Ash Concrete. According to comparative results of tensile strengths, the splitting tensile strength of fly-Ash Concrete can be predicted by using the JSCE design formula. In addition, the results indicate the uniaxial tensile strength of fly-Ash Concrete is higher than the splitting tensile strength at all test ages. A relationship between splitting strength and uniaxial strength, proposed by Yoshimoto, gives a conservative estimate for the evaluation of fly-Ash Concrete cracking strength.
