The Experts below are selected from a list of 15318 Experts worldwide ranked by ideXlab platform
Yingzi Wang - One of the best experts on this subject based on the ideXlab platform.
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experimental study on urban refuse magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
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Experimental study on urban refuse/magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
Guozhong Li - One of the best experts on this subject based on the ideXlab platform.
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experimental study on urban refuse magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
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Experimental study on urban refuse/magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
Yanzhen Yu - One of the best experts on this subject based on the ideXlab platform.
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experimental study on urban refuse magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
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Experimental study on urban refuse/magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
Jianquan Li - One of the best experts on this subject based on the ideXlab platform.
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experimental study on urban refuse magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
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Experimental study on urban refuse/magnesium oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the Production technology of urban refuse magnesium oxychloride cement compound floor tile by taking urban refuse and magnesium oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of magnesium chloride solution and the fineness of magnesium oxychloride cement on the property of the Product by means of experiments and analyzed the microstructure of Hydration Product using SEM.
Jeffrey J Thomas - One of the best experts on this subject based on the ideXlab platform.
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kinetic mechanisms and activation energies for Hydration of standard and highly reactive forms of β dicalcium silicate c2s
Cement and Concrete Research, 2017Co-Authors: Jeffrey J Thomas, Sam Ghazizadeh, Enrico MasoeroAbstract:Abstract The activation energy for Hydration of β –C 2 S paste was measured as a function of Hydration time using a calorimetric method and was found to depend on the surface area and reactivity of the powder as well as on the addition of sodium silicate. For neat paste made with standard β –C 2 S (similar to that found in portland cement), the activation energy is approximately 32 kJ/mol and is constant with time. For neat paste made with reactive β –C 2 S (calcined at lower temperature and with high surface area), the activation energy is about 55 kJ/mol and is also constant with time. This large difference in activation energy reflects a difference in the rate-controlling step for Hydration. After investigating the effects of sodium silicate and synthetic calcium–silicate–hydrate on the kinetics, we hypothesize that the lower activation energy represents C 2 S dissolution, while the higher value represents nucleation and growth of Hydration Product.
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time dependent driving forces and the kinetics of tricalcium silicate Hydration
Cement and Concrete Research, 2015Co-Authors: Jeffrey W Bullard, George W Scherer, Jeffrey J ThomasAbstract:Abstract Simulations of tricalcium silicate (C 3 S) Hydration using a kinetic cellular automaton program, HydratiCA, indicate that the net rate depends both on C 3 S dissolution and on Hydration Product growth. Neither process can be considered the sole rate-controlling step because the solution remains significantly undersaturated with respect to C 3 S yet significantly supersaturated with respect to calcium silicate hydrate (C–S–H). The reaction rate peak is attributed to increasing coverage of C 3 S by C–S–H, which reduces both the dissolution rate and the supersaturation of C–S–H. This supersaturation dependence is included in a generalized boundary nucleation and growth model to describe the kinetics without requiring significant impingement of Products on separate cement grains. The latter point explains the observation that paste Hydration rates are insensitive to water/cement ratio. The simulations indicate that the Product layer on C 3 S remains permeable; no transition to diffusion control is indicated, even long after the rate peak.
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influence of nucleation seeding on the Hydration mechanisms of tricalcium silicate and cement
Journal of Physical Chemistry C, 2009Co-Authors: Jeffrey J Thomas, Hamlin M Jennings, Jeffrey ChenAbstract:The fundamental chemical Hydration process of portland cement and its main mineral component, tricalcium silicate, was studied by investigating the effects of various additives. A relatively small amount (1−4 wt %) of well-dispersed calcium silicate hydrate (C−S−H), a pure form of the main Hydration Product, significantly increases both the early Hydration rate and the total amount of Hydration during the early nucleation and growth period (the first ∼24 h), as measured by calorimetry. This is attributed to a seeding effect whereby the C−S−H additive provides new nucleation sites within the pore space away from the particle surfaces. This mechanism is verified by a digital simulation of the Hydration process that reproduces key features of the Hydration kinetics. The results provide strong evidence that the Hydration process is autocatalytic such that the C−S−H gel Product stimulates its own formation. The seeding effect of C−S−H also provides a new explanation of the Hydration-accelerating effects of var...
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a new approach to modeling the nucleation and growth kinetics of tricalcium silicate Hydration
Journal of the American Ceramic Society, 2007Co-Authors: Jeffrey J ThomasAbstract:The Hydration kinetics of tricalcium silicate (C3S), the main constituent of portland cement, were analyzed with a mathematical “boundary nucleation” model in which nucleation of the Hydration Product occurs only on internal boundaries corresponding to the C3S particle surfaces. This model more closely approximates the C3S Hydration process than does the widely used Avrami nucleation and growth model. In particular, the boundary model accounts for the important effect of the C3S powder surface area on the Hydration kinetics. Both models were applied to isothermal calorimetry data from hydrating C3S pastes in the temperature range of 10°–40°C. The boundary nucleation model provides a better fit to the early Hydration rate peak than does the Avrami model, despite having one less varying parameter. The nucleation rate (per unit area) and the linear growth rate of the Hydration Product were calculated from the fitted values of the rate constants and the independently measured powder surface area. The growth rate follows a simple Arrhenius temperature dependence with a constant activation energy of 31.2 kJ/mol, while the activation energy associated with the nucleation rate increases with increasing temperature. The start of the nucleation and growth process coincides with the time of initial mixing, indicating that the initial slow reaction period known as the “induction period” is not a separate chemical process as has often been hypothesized.
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Deterioration of the nitrogen BET surface area of dried cement paste with storage time
Advanced Cement Based Materials, 1996Co-Authors: Robert L. Rarick, Jeffrey J Thomas, B. J. Christensen, Hamlin M JenningsAbstract:Abstract Gas sorption surface area measurements have been important for developing microstructural models for the structure of calcium-silicate-hydrate (C-S-H), the major Hydration Product of portland cement. However, surface area measurements using the nitrogen BET method have historically had high variability and have not always been reproducible. In this study, the variability of the nitrogen BET surface area of hardened cement paste (HCP) was investigated by varying the D-drying time and by storing the dried cement for various times before the BET measurement. The surface area of the samples was found to decrease with increasing storage time, and the surface area values became independent of the initial D-drying time after about 2 weeks. The storage time accounted for most of the observed variation in the data.
