【摘 要】
：
For the time variation of C-S-H microstructure in steam curing concrete precast members and mass concrete, by using curing regime that simulates variable temperature process in interior of mass concre
【机 构】
：
College of Materials Science and Engineering, North China University of Science and Technology, Tang
【出 处】
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The 14th International Congress on the Chemistry of Cement (
论文部分内容阅读
For the time variation of C-S-H microstructure in steam curing concrete precast members and mass concrete, by using curing regime that simulates variable temperature process in interior of mass concrete, and the 29Si and 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) combined with deconvolution technique,effect of fly ash content (0, 10, 30, 50wt%) under constant temperature of 20℃ or variable temperature regime on C-S-H microstructure were comparatively studied.The results indicate that the mean chain length (MCL) of C-S-H and degree of Al3+ substituting for Si4+ (Al[4]/Si) are significantly influenced by mixing amount and rcaction degree of fly ash.Under constant temperature of 20℃, the increase of fly ash content results in the increase of the MCL of C-S-H and Al[4]/Si, which both peak at fly ash content of 50%.Under variable temperature regime, the MCL of C-S-H and Al[4]/Si are both increased by elevated temperature at any content of fly ash, and with the increasing content of fly ash, the increase amplitude of the MCL of C-S-H increases,whereas the increase amplitude of Al[4]/Si reaches the maximum at fly ash content of 30%.This provides a theoretical basis for judging the fly ash content in mass concrete.
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