骨料含量和界面区体积对混凝土氯离子扩散性能的影响

Influence of Aggregate Contents and Volume of Interfacial Transition Zone on Chloride Ion Diffusion Properties of Concrete

将混凝土视为由骨料、界面区和砂浆所组成的三相复合材料,利用MATLAB软件建立混凝土粗骨料随机模型.把模型导入COMSOL软件,通过设定不同骨料含量和界面区体积,来探究这2种因素对氯离子在混凝土中扩散的影响.首先借助试验设计方法验证了所建立的随机模型的重复性和再现性,进而确定了其模拟精度,并通过与试验数据的对比分析,验证了上述方法的有效性;随后展开了骨料含量和界面区体积对混凝土氯离子扩散性能影响的模拟试验.模拟结果表明:氯离子在混凝土中的扩散受骨料含量和界面区体积的影响;骨料含量的增加抑制了氯离子的扩散性能,表现为骨料的曲折效应;界面区体积的增加加速了氯离子的扩散性能,表现为界面效应;随着骨料含量的增加,界面效应越来越明显.

In the previous paper,concrete was considered as a three-phase composite material consisting of aggregates,interfacial transition zone and mortar,and the random delivery model of concrete aggregate was established by MATLAB software.The model was introduced into COMSOL software,and the effect of different aggregate content and volume of interfacial transition zone on chloride ions diffusion was investigated.By means of design of experiment,the repeatability of the proposed model was verified and simulation precision was confirmed.The effectiveness of the model was tested by the comparative analysis of experimental data and simulated results.The simulation results show that the diffusion of chloride ions is restrained with increase of aggregate content,which is manifested by zigzag effect of the aggregate;the chloride ions diffusion is accelerated with volume of interfacial transition zone increase,which is assumed as interface effect.With the increase of aggregate content,the interface effect becomes more and more obvious.