摘要
利用RCM加速氯离子扩散法来预测界面过渡区(ITZ)对水泥基材料氯离子扩散性的影响规律.为了初步判断试样界面过渡区的氯离子扩散性能,并且了解骨料类型对水泥基材料传输性能的影响规律,取3种加工成立方体的粗骨料(玄武岩、花岗岩和砂岩)来制备混凝土试件,与相同配比的砂浆基体试样进行对比分析.结果表明,相同配比的情况下,含骨料试件比砂浆试件扩散系数大,且含花岗岩的试样氯离子扩散系数最低,说明界面过渡区对于水泥基材料的氯离子扩散性存在一定影响.能谱元素线分析结果表明,花岗岩与水泥砂浆基体间界面区厚度较小,约为35μm,且比较密实,对水泥基材料的扩散性能影响最小.采用离散单元法建立的三维骨料的随机分布模型,最初的模拟结果可较为直观地分析介质在界面区的扩散路径,并为以后骨料集合体通过扩散路径的长度、迂曲度的变化影响扩散速度的研究工作打下基础.
The rapid chloride migration(RCM) test is applied to investigate the influence of interfacial transition zone(ITZ) to the chloride diffusibility of cemented materials.In order to investigate the chloride migration property of percolated ITZ on the chloride migration coefficient of specimens,specimens with three types of cubic aggregates(basalt,granite,sandstone) were cast and tested.Based on the experimental results,the chloride migration coefficients of specimens with coarse aggregates are higher than those of mortar matrix,which show that the ITZ can influence the chloride diffusibility of cemented materials.For three types of aggregates,specimens with granite have the best property of resisting chloride migration because the ITZ between granite and mortar matrix is denser than others.The energy dispersive spectrum(EDS) elemental line analysis results show that the thickness of the interfacial zone between the granite and cement mortar matrix is about 35μm and denser than others,which has minimal effect on the diffusibility properties of cemented materials.The random three-dimensional aggregate model based on the discrete element method can interpret the diffusion path of the ITZ.This model can also lay a foundation for the study such as diffusion path length,tortuosity and tortuous diffusion velocity.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2009年第S2期268-273,共6页
Journal of Southeast University：Natural Science Edition
基金
国家重点基础研究发展计划(973计划)资助项目(2009CB623200)
关键词
界面过渡区
氯离子扩散系数
RCM
扩散性能
interfacial transition zone
chloride diffusivity coefficient
rapid chloride migration
diffusibility
