Quantitative analysis of pure triclinic tricalcium silicate and C–S–H gels by 29Si NMR longitudinal relaxation time
Quantitative analysis of pure triclinic tricalcium silicate and C–S–H gels by 29Si NMR longitudinal relaxation time
复制标题
通过 29Si NMR 纵向弛豫时间定量分析纯三斜硅酸三钙和 C-S-H 凝胶
DOI：
10.1016/j.conbuildmat.2015.12.146
复制
发表时间：
2016
影响因子：
7.4
通讯作者：
M. Blanco
中科院分区：
文献类型：
--
作者：
I. F. S. D. Bosque;M. Martín;I. Sobrados;S. Martínez;M. Blanco
29 Si魔角自旋核磁共振（29 Si MAS NMR）常用于监测硅酸三钙（C3 S）的水化程度和水化过程中生成的水化硅酸钙（C-S-H凝胶）的结构，水化硅酸钙对水泥浆体的强度和耐久性有重要影响。本研究旨在测量无水三斜晶系C3 S结构中不同类型Si的纵向弛豫时间（T1），水化后数天的浆体中剩余的C3 S和水化产物（C-S-H凝胶）。结果表明，水合后剩余的C3 S的29 Si信号的纵向弛豫时间明显短于起始材料的无水C3 S相;这种效应被解释为周围水分子提供的29 Si-1H偶极弛豫的额外贡献。有趣的是，较短的T1的剩余的非水合C3 S，这是可比的C-S-H凝胶允许更快的收购quantitative 29 Si MAS光谱。
29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR) has been commonly used to monitor the hydration degree of tricalcium silicate (C3S) and the structure of the calcium silicate hydrate known as C–S–H gel generated during their hydration, which is responsible for the strength and durability of cement pastes. The present study is aimed to measure the longitudinal relaxation times (T1) for the different types of Si in the structure of anhydrous triclinic C3S, the remnant C3S in pastes after a number of hydration days and the hydrated product (C–S–H gel). Results showed that the longitudinal relaxation times of the29Si signals of C3S remaining after hydration are considerably shorter than the anhydrous C3S phase of the starting material; an effect that was interpreted as an extra contribution of29Si–1H dipolar relaxation provided by the surrounding water molecules. Interestingly, the shorterT1of the remaining non-hydrated C3S which is comparable to the C–S–H gel permits a much faster acquisition of quantitative29Si MAS spectra.