Microstructural changes in white Portland cement paste under the first drying process evaluated by WAXS, SAXS, and USAXS
Microstructural changes in white Portland cement paste under the first drying process evaluated by WAXS, SAXS, and USAXS
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DOI：
10.1016/j.cemconres.2016.10.002
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发表时间：
2017-01-01
影响因子：
11.4
通讯作者：
Igarashi, Go
中科院分区：
文献类型：
--
作者：
Maruyama, Ippei;Sakamoto, Naoki;Igarashi, Go
采用小角X射线散射（q = 0.017 nm（-1）~ 30 nm（-1））方法，结合分形圆盘状颗粒分析和Guinier近似，研究了不同相对湿度（RH）条件下缓慢干燥1.5年的水泥石中细观和微观结构的变化。分形盘状颗粒分析表明，硅酸钙水合物（C-S-H）团聚体是非常薄的（类似于2.5 nm）和相对较大的宽度（类似于35 nm）在高RH条件下。然而，在40%的RH下，团聚体被分段（宽度）成类似于10 nm。Guinier近似发现，在2nm（-1）~ 8 nm（-1）范围内的散射分布可能对应于C-S-H单分子层之间的间距，并且在40%~ 50%RH范围内呈现阶梯式变化。C-S-H单分子层之间的距离的逐步行为可以解释在40%RH左右的水蒸气解吸的扭结。(C)2016爱思唯尔有限公司版权所有
Meso- and micro-scale structural changes in matured hardened cement paste dried slowly for 1.5 years at different relative humidities (RHs) are evaluated by small-angle X-ray scattering profiles covering a q range of 0.017 nm(-1)-30 nm(-1) with a fractal disc-shaped particle analysis and Guinier approximation. The fractal disc-shaped particle analysis revealed that calcium-silicate-hydrate (C-S-H) agglomerations are very thin (similar to 2.5 nm) and of relatively large width (similar to 35 nm) under high RH conditions. However, the agglomerations are segmented (in width) into similar to 10 nm below an RH of 40%. The Guinier approximation found the possibility that the scattering profiles in the range of 2 nm(-1)-8 nm(-1) correspond to a spacing between C-S-H monolayers and it showed stepwise changes at 40%-50% RH. The stepwise behavior of the distance between C-S-H monolayers may explain a kink in water vapor desorption at around 40% RH. (C) 2016 Elsevier Ltd. All rights reserved.