水泥–矿渣复合胶凝材料中矿渣的水化特性

通过对不同矿渣掺量时水泥–矿渣复合胶凝材料中矿渣的反应程度、硬化浆体中Ca（OH）2含量以及水化硅酸钙（C–S–H）凝胶的Ca/Si比（Ca和Si的摩尔比）的测定,研究复合胶凝材料体系中矿渣的水化特性。结果表明：在水泥–矿渣复合胶凝材料中,矿渣掺量越大,矿渣反应程度越低,但矿渣掺量≤70%时,对矿渣的反应程度影响不大。高温养护可提高早期矿渣的反应程度,但阻碍其后期的进一步水化。矿渣早期水化生成外部水化产物时消耗一定的Ca（OH）2,使硬化浆体中Ca（OH）2含量降低,矿渣水化吸收Ca（OH）2中的Ca2＋,使生成的C–S–H凝胶的Ca/Si比降低较少;在水化后期,矿渣生成内部水化产物不再消耗较多的Ca（OH）2,使C–S–H凝胶的Ca/Si比降低相对较多,硬化浆体中Ca（OH）2含量有增加的趋势,保证硬化浆体的长期稳定性。

Hydration Characteristics of Slag in Cement-Slag Complex Binder

The hydration characteristics of slag in cement-slag binder at different slag ratios were investigated via measurements of reaction degree of slag,Ca(OH)2 content in hardened paste and mole ratio of Ca to Si of formed silicate calcium hydrate(C-S-H) gel.The results show that a greater slag ratio in cement-slag binder leads to a lower reaction degree of slag,and the effect of slag ratio on the slag reaction degree is not obvious within certain limits(≤70%).High temperature could improve the slag reaction degree in early hydration time,but it hindered the further hydration in late hydration time.Since some of Ca(OH)2 was consumed when the outer hydrate was formed in early hydration time,the Ca(OH)2 content in the hardened paste was thus decreased.Also,Ca/Si ratio in C-S-H gel was decreased slightly after slag absorbed Ca2+ from Ca(OH)2.In the late hydration time,a certain amount of Ca(OH)2 was not consumed when the inner hydrate was formed,then leading to that Ca/Si ratio in C-S-H gel decreased and Ca(OH)2 content tended to increase in the hardened paste.This result can ensure the stability of the hardened paste in long ages.