盐冻作用下风积沙混凝土中氯离子扩散研究

为研究氯盐冻融循环作用下风积沙掺量对混凝土氯离子扩散的影响,试验制备了不同风积沙掺量(质量替代率为0％、25％、50％、75％、100％)的混凝土.通过化学分析法测定盐冻环境下不同风积沙掺量混凝土中自由氯离子浓度和总氯离子浓度,计算了风积沙混凝土相对氯离子结合系数和氯离子扩散系数.结果表明:自由氯离子浓度随风积沙掺量的...

Chloride Ion Diffusion in Aeolian Sand Concrete under Salt Freezing

Concrete specimens with different aeolian sand content (mass substitution rate 0%, 25%, 50%, 75%, 100%) were prepared to conduct experimental research on the effect of aeolian sand content on chloride ion diffusion in concrete under cyclic freezing and thawing of chloride salt. The free chloride ion concentration and total chloride ion concentration in concrete with different aeolian sand contents under salt freezing environment were determined by chemical analysis method, and the relative chloride ion binding coefficient and chloride ion diffusion coefficient of aeolian sand concrete were calculated. Results revealed that the free chloride ion concentration declined at first but then increased with the augment of aeolian sand content, while gradually increased with the proceeding of cyclic freezing and thawing. The binding performance of aeolian sand concrete showed good Langumir nonlinear adsorption and had no direct relationship with freeze-thaw cycles. When the content of aeolian sand was 25%, the relative chloride ion binding coefficient was the smallest. The chloride ion diffusion coefficient hit the lowest value under the same freeze-thaw cycles. Cyclic freezing and thawing had little effect on the diffusion rate of chloride ion in concrete with large content of aeolian sand. The diffusion coefficient of chloride ion of the test group with 100% aeolian sand content decreased with the proceeding of freeze-thaw cycles, displaying good resistance to chloride ion erosion. Proper amount of aeolian sand could better resist chloride ion invasion, and a large amount of aeolian sand could boost the frost resistance of concrete under chloride salt erosion.