Ion-cement hydrate interactions govern multi-ionic transport model for cementitious materials
Ion-cement hydrate interactions govern multi-ionic transport model for cementitious materials
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DOI：
10.1016/j.cemconres.2010.08.019
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发表时间：
2010-12-01
影响因子：
11.4
通讯作者：
Kurumisawa, K.
中科院分区：
文献类型：
--
作者：
Elakneswaran, Y.;Iwasa, A.;Kurumisawa, K.
本研究的主要目的是描述水泥水合物和电解质溶液之间的相互作用，以了解多离子在胶凝材料中的传输。采用PHREEQC中的表面络合模型，考虑静电作用，模拟了水合硅酸钙（C-S-H）表面的离子吸附。通过对实验数据的拟合，得到了离子在C-S-H表面的吸附平衡常数。二价和一价阳离子以及阴离子的吸附显著改变了水化浆体的表面电荷。氯化物以弗里德尔盐的形式进行化学结合，主要通过C-S-H的吸附作用进行结合。采用相平衡模型，表面络合模型和多组分扩散模型的综合建模方法已在PHREEQC中开发，以模拟通过水化水泥浆体的多离子输运。结果表明，离子在C-S-H上的物理吸附、孔的大小和C-S-H的表面位密度决定了离子物种的渗透速率。最后，所提出的模型已被验证对氯离子剖面测量在这项研究中，以及在文献中的数据水合水泥浆。皇冠版权所有（C）2010由爱思唯尔有限公司出版。保留所有权利。
The main objective of this investigation is to describe the interaction between cement hydrates and electrolyte solution to understand multi-ionic transport in cementitious materials. A surface complexation model in PHREEQC including an electrostatic term is used to simulate the ionic adsorption on the calcium silicate hydrate (C-S-H) surface. The equilibrium constants for the adsorption of ions on C-S-H surfaces are obtained by fitting experimental data to the model. The adsorption of both divalent and mono-valent cations, and also anions significantly changes the surface charges of hydrated paste. Chloride is being held in a chemical binding as Friedel's salt and bound mainly by the adsorptive action of C-S-H. An integrated modelling approach employing a phase-equilibrium model, a surface complexation model, and a multicomponent diffusion model has been developed in PHREEQC to simulate the multi-ionic transport through hydrated cement paste. It was found that the physical adsorption of ions on C-S-H, the size of pores, and the surface site density of C-S-H govern the rate of penetration of ionic species. Finally, the proposed model has been validated against chloride profiles measured in this study as well as with data available in the literature for hydrated cement paste. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.