35%荷载、干湿循环对混凝土氯离子扩散系数的影响

Influnce of 35% load,dry-wet cycle on concrete diffusion coefficient

采用盐湖卤水分别进行长期浸泡、干湿循环、浸泡-35%荷载腐蚀试验,定期检测了混凝土不同深度的自由氯离子含量,应用二维氯离子扩散定律和Fick第二定律计算了混凝土氯离子扩散系数和混凝土的寿命,分析了水灰比和试验环境对表面氯离子扩散系数的影响。结果表明,氯离子扩散系数随着水灰比的增大而增大,与长期浸泡相比,干湿循环和施加35%荷载都加速了混凝土表面氯离子扩散系数,干湿循环的效果更明显,在盐湖环境下采用高强混凝土是提高混凝土耐久性的有效方法。

Immersion,dry-wet cycle and immersion-35%load in salt lake brine was adopted to periodically test chloride ion concent at different depths of concrete and concrete chloride diffusion coefficient and concrete life was computed with Fick second low and 2-D chlo-ride diffusion model.Effect of water to cement ratio and test condition on concrete chloride diffusion coefficient were also analyzed.Test results show that chloride ion diffusion coefficient increases with the increase of water to cement ratio;both dry-wet cycle and 35%load accelerate chloride ion diffusion coefficient comparation with inmmersion and dry-wet cycle is more obvious.High strength concrete as an effective method to improve concrete life in salt lake enviroment.