A model for dissolution of CaO-SiO2-H2O gel at Ca/Si > 1

被引：27
作者：
Rahman, MM [1 ]
Nagasaki, S [1 ]
Tanaka, S [1 ]
机构：
[1] Univ Tokyo, Dept Quantum Engn & Syst Sci, Bunkyo Ku, Tokyo 1138656, Japan
来源：
CEMENT AND CONCRETE RESEARCH | 1999年 / 29卷 / 07期
关键词：
C-S-H gel; Margules type solid; dissolution; conditional solubility product;
D O I：
10.1016/S0008-8846(99)00092-7
中图分类号：
TU [建筑科学];
学科分类号：
0813 ;
摘要：
Calcium silicate hydrate (CaO-SiO2-H2O) gel is the principal hydration product of Portland cement. Experimental data show that the dissolution of CaO-SiO2-H2O (C-S-H) gel is strongly dependent on Ca/Si (C/S) ratio in the range of C/S > 1. A model for dissolution of C-S-H eel is presented by considering a nonideal mixture of binary solid solutions of Margules type. Guggenheim and Prausnitz equations are applied to represent the activities of model solids as a function of mole fractions. The Gibbs-Duhem equation, incorporating the activities of model solids, is then used to express the conditional solubility products of model solids in terms of CIS ratio. The determination of Guggenheim's empirical parameters is performed with geochemical code PHREEQE on experimental data. By these procedures, a dissolution model of C-S-H gel is described. The solubility results predicted by the proposed model are comparable with experimental data. (C) 1999 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码：1091 / 1097
页数：7
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