干湿循环条件混凝土内氯离子输运试验拟合与分析

为了进一步揭示干湿循环条件下氯离子在混凝土中的输运机理,对比分析全浸泡和干湿循环两种条件下的已有试验数据,分开考虑浓度扩散作用和孔隙吸附作用,对混凝土内氯浓度的分布与侵入深度和侵蚀时间的关系进行拟合,得到氯离子浓度随时间和深度变化的经验公式.比较不同水灰比及掺粉煤灰混凝土的试验数据与公式计算数据,拟合情况较好.该式在传统扩散模型基础上引入了孔吸附作用,更符合工程实际多种因素共同作用的情况.

Fitting research and analysis of chloride transport experiment in concrete under wetting and drying cycle

To further disclose the transport mechanism of chloride in concrete under cyclic wetting and drying conditions, based on the comparison of experiment data from entire immersion and wetting-drying cycle, a nonlinear fitting is made to obtain the empirical formula of chloride concentration changing with invading depth and corrosion time, which considers concentration diffusion and pore adsorption separately. Experiment data are in good agreement with data calculated by the formula for different water cement ratio and concrete adulterated with fly ash. Introducing the effect of pore adsorption into traditional diffusion model, the formula can better accord with the engineering practical situation being acted by multiple factors.