The Experts below are selected from a list of 1017 Experts worldwide ranked by ideXlab platform
Taner Kavas - One of the best experts on this subject based on the ideXlab platform.
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Physico-chemical characteristics of chemically activated cement containing boron
Building and Environment, 2007Co-Authors: Ali Olgun, Taner Kavas, Y. Erdogan, G. OnceAbstract:Abstract The use of colemanite ore waste (CW) containing boron as a cement replacement material increases the long-term strength of the concrete. Despite this benefit, the use of CW is limited due to the low-early strength of the CW concrete. The study reported below intended to eliminate this problem. The experimental part comprises two stages: in the first stage the possibility of using CW instead of Natural Gypsum has been investigated through several tests. In the second stage, a number of chemical activators, namely, sulphonated melamine formaldehyde (SMF) condensates, sulphonated naphthalene formaldehyde (SNF) condensates, Na 2 SO 4 , and calcium chloride were used. The results showed that replacement of Natural Gypsum by CW results in an acceptable initial and final setting time of cement and increases the compressive strength of the mortar at long term. The addition of chemical activators into the system accelerated pozzolanic reaction and considerably increased early strength of the mortars. The results also indicate that chemical activators not only alter the rate of cement paste hydration, but the microstructure of mortar as well.
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setting and hardening of boroGypsum portland cement clinker fly ash blends studies on effects of molasses on properties of mortar containing boroGypsum
Cement and Concrete Research, 2005Co-Authors: Taner Kavas, A Olgu, Y ErdogaAbstract:Abstract The present work describes a study of setting and hardening of blends of boroGypsum, fly ash, and Portland cement clinker (PC). The possibility of using boroGypsum instead of Natural Gypsum in fly ash–cement matrix has been investigated through several tests. In addition, the effects of molasses on the setting times of cement and strength of the mortar were also studied. The setting times of the cement were retarded when the Natural Gypsum was replaced by boroGypsum. Molasses exhibited a rather significant retarding effect when used in combination with boroGypsum in cement. The inclusion of molasses to the system at a level of 0.1% resulted in a reduction in early strength of the mortar. However, it significantly enhanced the strength of the mortar after 7 days of curing age. In general, the cement prepared with boroGypsum was found to have similar strength properties to those obtained with Natural Gypsum, and inclusion of molasses into the system significantly increased the strength of the sample after 7 days of curing age.
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Setting and hardening of boroGypsum–Portland cement clinker–fly ash blends. Studies on effects of molasses on properties of mortar containing boroGypsum
Cement and Concrete Research, 2005Co-Authors: Taner Kavas, Ali Olgun, Y. ErdoganAbstract:Abstract The present work describes a study of setting and hardening of blends of boroGypsum, fly ash, and Portland cement clinker (PC). The possibility of using boroGypsum instead of Natural Gypsum in fly ash–cement matrix has been investigated through several tests. In addition, the effects of molasses on the setting times of cement and strength of the mortar were also studied. The setting times of the cement were retarded when the Natural Gypsum was replaced by boroGypsum. Molasses exhibited a rather significant retarding effect when used in combination with boroGypsum in cement. The inclusion of molasses to the system at a level of 0.1% resulted in a reduction in early strength of the mortar. However, it significantly enhanced the strength of the mortar after 7 days of curing age. In general, the cement prepared with boroGypsum was found to have similar strength properties to those obtained with Natural Gypsum, and inclusion of molasses into the system significantly increased the strength of the sample after 7 days of curing age.
Y. Erdogan - One of the best experts on this subject based on the ideXlab platform.
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Physico-chemical characteristics of chemically activated cement containing boron
Building and Environment, 2007Co-Authors: Ali Olgun, Taner Kavas, Y. Erdogan, G. OnceAbstract:Abstract The use of colemanite ore waste (CW) containing boron as a cement replacement material increases the long-term strength of the concrete. Despite this benefit, the use of CW is limited due to the low-early strength of the CW concrete. The study reported below intended to eliminate this problem. The experimental part comprises two stages: in the first stage the possibility of using CW instead of Natural Gypsum has been investigated through several tests. In the second stage, a number of chemical activators, namely, sulphonated melamine formaldehyde (SMF) condensates, sulphonated naphthalene formaldehyde (SNF) condensates, Na 2 SO 4 , and calcium chloride were used. The results showed that replacement of Natural Gypsum by CW results in an acceptable initial and final setting time of cement and increases the compressive strength of the mortar at long term. The addition of chemical activators into the system accelerated pozzolanic reaction and considerably increased early strength of the mortars. The results also indicate that chemical activators not only alter the rate of cement paste hydration, but the microstructure of mortar as well.
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Setting and hardening of boroGypsum–Portland cement clinker–fly ash blends. Studies on effects of molasses on properties of mortar containing boroGypsum
Cement and Concrete Research, 2005Co-Authors: Taner Kavas, Ali Olgun, Y. ErdoganAbstract:Abstract The present work describes a study of setting and hardening of blends of boroGypsum, fly ash, and Portland cement clinker (PC). The possibility of using boroGypsum instead of Natural Gypsum in fly ash–cement matrix has been investigated through several tests. In addition, the effects of molasses on the setting times of cement and strength of the mortar were also studied. The setting times of the cement were retarded when the Natural Gypsum was replaced by boroGypsum. Molasses exhibited a rather significant retarding effect when used in combination with boroGypsum in cement. The inclusion of molasses to the system at a level of 0.1% resulted in a reduction in early strength of the mortar. However, it significantly enhanced the strength of the mortar after 7 days of curing age. In general, the cement prepared with boroGypsum was found to have similar strength properties to those obtained with Natural Gypsum, and inclusion of molasses into the system significantly increased the strength of the sample after 7 days of curing age.
Y Erdoga - One of the best experts on this subject based on the ideXlab platform.
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setting and hardening of boroGypsum portland cement clinker fly ash blends studies on effects of molasses on properties of mortar containing boroGypsum
Cement and Concrete Research, 2005Co-Authors: Taner Kavas, A Olgu, Y ErdogaAbstract:Abstract The present work describes a study of setting and hardening of blends of boroGypsum, fly ash, and Portland cement clinker (PC). The possibility of using boroGypsum instead of Natural Gypsum in fly ash–cement matrix has been investigated through several tests. In addition, the effects of molasses on the setting times of cement and strength of the mortar were also studied. The setting times of the cement were retarded when the Natural Gypsum was replaced by boroGypsum. Molasses exhibited a rather significant retarding effect when used in combination with boroGypsum in cement. The inclusion of molasses to the system at a level of 0.1% resulted in a reduction in early strength of the mortar. However, it significantly enhanced the strength of the mortar after 7 days of curing age. In general, the cement prepared with boroGypsum was found to have similar strength properties to those obtained with Natural Gypsum, and inclusion of molasses into the system significantly increased the strength of the sample after 7 days of curing age.
Guan Xiao-dong - One of the best experts on this subject based on the ideXlab platform.
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Properties of Gypsum Produced in Rapid Wet Desulphurizing Process from Off-gas of Thermal Power Plant
Nonferrous Metals, 2004Co-Authors: Guan Xiao-dongAbstract:The properties of the FGD Gypsum produced in rapid wet desulphurizing process from thermal power plant off-gas is investigated by means of particle size analysis, DTA and XRD analysis. The results show that the mechanical and chemical properties and mineral composition of FGD Gypsum are extremely similar to the Natural Gypsum, which provides the effective approach to FGD Gypsum comprehensive utilization.
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Gypsum from Rapid Wet Desulphurizing Process as Cement Retarder
Nonferrous Metals, 2004Co-Authors: Guan Xiao-dongAbstract:The application of FGD Gypsum product as the cement setting retarder is investigated. The FGD Gypsum similar to the Natural Gypsum in common characteristics, and is adequately used as cement retarder. The FGD Gypsum should be dried at low temperature for the use of cement retarder. The various cement products with FGD Gypsum as cement retarder are consonant with the relevant national standards. It is effective way for disposal of desulphurizing product from fire power station.
Jiangsen Liu - One of the best experts on this subject based on the ideXlab platform.
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Research on degradation mechanisms of recycled building Gypsum
Construction and Building Materials, 2018Co-Authors: Cong Zhu, Jianxin Zhang, Cao Wenxiang, Jiahui Peng, Jiangsen LiuAbstract:Abstract In order to provide a solid theoretical foundation for the efficient reuse of waste Gypsum, the research on the degradation mechanisms of recycled Gypsum mechanical performance was carried out in this paper. The recycled Gypsum was prepared with Natural Gypsum ores in the laboratory and three rational comparative methods were proposed through constraining the conditions: the preparation process, the particle size distribution and the water/Gypsum ratio. The results showed that the recycled dihydrate Gypsum was much easier to grind than the Natural Gypsum ores, resulting in deteriorated particle size distribution, large specific surface area and void fraction, poor sphericity, which remarkably increased the water requirement. The increase in porosity and larger pore size due to excessive water evaporation was the determining factor leading to a significant decrease in the strength of the recycled Gypsum. However, the short columnar shape crystals seemly would only have a slight disadvantageous on the flexural strength. Moreover, the crystal morphological characteristics of dihydrate Gypsum had a decisive influence on the sphericity of recycled hemihydrate particles.
