摘要
利用Fick定律及质量守恒定律,并结合钙的固液平衡方程和氯离子吸附结合模型,建立了水泥净浆中氯离子和钙离子的耦合传输模型。通过与已有文献中氯盐-溶蚀耦合腐蚀实验的实测结果进行对比分析,验证了耦合传输模型的合理性,并在此基础上,以氯盐-溶蚀耦合作用下水泥净浆薄板试件为例,利用验证后的模型,计算分析了薄板试件孔溶液中钙离子浓度、自由氯离子含量及孔隙率的时空分布规律。结果表明,试件孔隙率及氯离子传输速率均随着氢氧化钙的溶出而增加,且氯盐-钙溶蚀耦合作用下试件中自由氯离子含量显著高于单一氯盐侵蚀,故钙溶蚀加快了氯离子在水泥净浆内的扩散传输速率。
A coupling diffusion model of chloride ions and calcium ions in hardened cement paste was proposed by using the Fick laws,mass conservation law,equilibrium relationship between solid calcium and calcium ion,as well as the binding equation of chloride ion.This model is verified via its calculated data and the measured results from the present literature.The numerical simulation for a hardened cement paste slice specimen under the coupling chloride attack and calcium leaching was performed to analyze the space-time changes of the calcium ion concentration in pore solution,free chloride content and the porosity in the specimen.Results show that both the porosity and chloride diffusion rate in the specimen increase with the dissolution of calcium hydroxide.The free chlorine content in the specimen is greater than that of single chloride attack,and the calcium leaching can leads to an increase in the chloride diffusivity in hardened cement pastes.
作者
张林松
左晓宝
汤玉娟
李向南
马强
ZHANG Linsong;ZUO Xiaobao;TANG Yujuan;LI Xiangnan;MA Qiang(Department of Civil Engineering,School of Science,Nanjing University of Science&Technology,Nanjing 210094,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2019年第2期184-191,共8页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(51778297)
关键词
耦合传输
模型
混凝土
钙溶蚀
氯盐侵蚀
数值分析
coupling diffusion
model
concrete
calcium leaching
chloride attack
numerical simulation
作者简介
第一作者:张林松(1994—),男,硕士研究生,E-mail:zhanglins302@163.com;通信作者:左晓宝(1968—),男,博士,教授,E-mail:xbzuo@sina.com。
