钢筋混凝土结构电场阻盐防护计算与验证

Calculation and examination of electric field retardation chloride used for reinforced concrete structure

根据氯盐环境中钢筋混凝土腐蚀破坏的机理,利用氯离子在电场作用下向外迁移的原理,从而阻滞其向混凝土内侵入,提出了钢筋混凝土结构物电场阻盐(ERC)防护新技术.对水灰比为0.45的混凝土试件进行了ERC试验,在0.75和1.00 V的电压下阻盐处理240 d时,氯离子侵入量分别下降39%和52%,结果证实了该技术阻止环境中氯离子侵入的有效性;采用有限元方法计算了ERC条件下混凝土中氯离子质量分数分布,计算结果与实测值基本吻合,相关系数达到0.98以上,表明理论计算结果较为可靠.计算分析了混凝土结构在0.75和1.00 V电压下,服役100 a时氯离子在混凝土中的分布,结果表明:在100 a的服役后混凝土保护层内氯离子含量明显低于钢筋腐蚀的临界浓度,因而可保持混凝土结构在100 a使用寿命内不因钢筋的腐蚀而破坏.

According to the mechanism of corrosion failure of reinforced concrete structure under salty environment, a new prevention technology for reinforced concrete structure is firstly put forward utilizing migration of chloride ion under electric field to retard chloride ingression into concrete. The electric field retardation chloride （ ERC ） test was made for concrete specimens with 0.45 w/c ratio at 0.75 V and 1. 00 V voltage for 240 days, and chloride content in concrete decreased by 39% and 52% respectively, which indicates that the ERC technique can retard chloride ingression into concrete. The chloride distribution in concrete was calculated based on numerical model of ERC by finite element method, showing that the calculation results are basically in agreement with the measured value, with correlation coefficients of 0.98 and more. The chloride distribution in concrete was calculated at the service life of 100 years with ERC, and the results show that chloride contents in concrete still keep a lower level than the critical one of the steel corrosion at the service life of 100 years.