Surface area changes in C3S paste during the first drying analyzed by 1H NMR relaxometry
Surface area changes in C3S paste during the first drying analyzed by 1H NMR relaxometry
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DOI：
10.1016/j.cemconres.2022.106762
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发表时间：
2022-03-05
影响因子：
11.4
通讯作者：
Ohkubo, Takahiro
中科院分区：
文献类型：
--
作者：
Maruyama, Ippei;Fujimaki, Tetsuya;Ohkubo, Takahiro
采用质子核磁共振弛豫法对水胶比为0.55的纯C3 S浆体在不同相对湿度条件下的干燥过程进行了监测。实验得到了层间水的脱附等温线。层间水含量和层间水的T-2值之间的关系定义了表面弛豫时间，这提供了关于吸附水的定量数据。根据快速交换模型，密封条件下的表面积为630 m2/g-水合硅酸钙（C-S-H），在干燥过程中表面积下降，这与化学结合水的增加有关。层间表面积的减少与化学结合水的增加之比为5400 m2/g。基于该值，计算C-S-H的总表面积为830至921 m2/g-C-S-H。
The drying process of pure C3S paste with a water to binder ratio of 0.55 under different relative humidity conditions was monitored using proton nuclear magnetic resonance relaxometry. The desorption isotherm of the interlayer water was obtained experimentally. The relationship between the interlayer water content and T-2 value of the interlayer water defines the surface relaxation time, which provides quantitative data regarding the adsorbed water. According to the fast exchange model, the surface area at the sealed condition was 630 m(2)/g-calcium silicate hydrate (C-S-H), and it decreased during drying, which was associated with an increase in chemically bound water. The ratio of the decrease in the interlayer surface area to the increase in chemically bound water was 5400 m(2)/g. Based on this value, the total surface area of C-S-H was calculated to 830 to 921 m(2)/g-C-S-H.