Multi-scale observations of structure and chemical composition changes of portland cement systems during hydration
Multi-scale observations of structure and chemical composition changes of portland cement systems during hydration
复制标题
DOI：
10.1016/j.conbuildmat.2019.04.013
复制
发表时间：
2019-07
影响因子：
7.4
通讯作者：
M. Moradian;Qinang Hu;Mohammed Aboustait;M. T. Ley;J. Hanan;Xianghui Xiao;V. Rose;R. Winarski;G. Scherer
中科院分区：
文献类型：
--
作者：
M. Moradian;Qinang Hu;Mohammed Aboustait;M. T. Ley;J. Hanan;Xianghui Xiao;V. Rose;R. Winarski;G. Scherer
关于水泥浆体从浆体到固体的转变机制和直接观察结果，人们几乎没有达成一致意见。本文采用四种不同的成像技术在多个长度尺度（从15.6 nm到1 μm）下跟踪波特兰水泥和单斜硅酸三钙（mC 3S）浆体在水化的前16 h内的三维微观结构演变。每10分钟捕获超过60，000个颗粒的测量在微米级进行。纳米尺度的结构和化学成分的检查是用来支持这项工作。结果表明，在加速期之前，水化产物在水化颗粒表面和附近形成，其平均Ca/Si > 3，加速期似乎控制了反应速率。这些水化产物似乎在化学组成上发生变化，因为在加速期间发生C3 S的更快速溶解和水化产物的形成。研究结果被用来提供洞察的起源的诱导和加速期在水合作用。
There is little agreement about the mechanisms and few direct observations of the transition of cement paste from a slurry to a solid. This paper uses four different imaging techniques at multiple length scales (from 15.6 nm to 1 μm) to follow the three-dimensional microstructural evolution of portland cement, and monoclinic tricalcium silicate (mC3S) paste over the first 16 h of hydration. Measurements of over 60,000 particles captured every 10 min were made at the micron scale. Nanoscale examinations of the structure and chemical composition are used to support this work. The results show that hydration products with an average Ca/Si > 3 form on and near the surface of the hydrating particles prior to the acceleration period that appears to control the reaction rate. These hydration products appear to change in chemical composition as more rapid dissolution of C3S and formation of hydration products occur during the acceleration period. The findings are used to provide insights into the origin of the induction and acceleration periods during hydration.