盐湖地区混凝土的氯离子扩散性

Chloride ion diffusivity of salt lake concrete

在盐湖轻盐渍土现场暴露试验和试验室盐湖卤水干湿循环试验中,采取分层钻孔取样和化学分析方法,应用氯离子三维扩散理论,研究普通混凝土、高强混凝土和高性能混凝土的Cl-扩散系数Dt的变化规律。研究结果表明:混凝土的Cl-扩散系数随着暴露时间的增加而降低,混凝土的抗Cl-扩散能力由大至小为高性能混凝土、高强混凝土、普通混凝土;Cl-扩散系数Dt随着水灰比的变小而变小,矿物掺合料(FA,SF和SL)可以降低Cl-扩散系数。

Through light salt soil field exposure experiment in the salt lake area and salt lake brine wetting-drying cycle test in the laboratory,through methods of stratified sampling and chemical analysis,permeability rule of chloride for ordinary Portland cement concrete（OPC）,high strength concrete（HSC） and high performance concrete（HPC） was studied using the three-dimensional chloride diffusion theory.The results show that chloride diffusion coefficient（Dt） increases with the decrease of exposure time.The order of the concretes with resisting chloride ion diffusivity from large to small is high performance concrete（HPC）,high strength concrete（HSC） and ordinary Portland cement concrete（OPC）.chloride diffusion coefficient（Dt） decreases with the decrease of water to binder ratio,and mineral admixture（FA,SF and SL） also reduces the chloride ion diffusion coefficient.