基于通电退化的再生混凝土中钢筋可靠性评估

为了评估阻锈剂对再生混凝土中钢筋的保护作用,设计了钢筋再生混凝土恒电流通电加速锈蚀试验,对再生混凝土中钢筋进行电化学试验,分析钢筋极化曲线及交流阻抗,计算钢筋腐蚀电流密度,并以腐蚀电流密度作为损伤变量,运用Weibull分布函数建立再生混凝土中钢筋的可靠度函数.钢筋通电加速试验后,对钢筋进行微观形貌观测.结果 表明:随着通电时间的增加,未掺阻锈剂的再生混凝土试件中钢筋表面出现颗粒状的锈蚀物;掺加阻锈剂的再生混凝土试件中钢筋表面出现大量的微裂纹;可靠度为60％时未掺和掺加阻锈剂试件中钢筋失效时间分别为880、2060 h,阻锈剂可以使再生混凝土使用寿命延长至原来的2.34倍.

Reliability Evaluation of Steel Bars in Recycled Concrete Based on Corrosion by Electric Current

In order to evaluate the protective effect of corrosion inhibitor on reinforcement in recycled concrete, the constant current electrification accelerated test of reinforced recycled concrete was designed. The electrochemical test was carried out on the reinforcement in concrete. The polarization curve and AC impedance of reinforcement were analyzed, and the corrosion current density was calculated. The corrosion current density was taken as the damage variable and degradation parameter, and the recycled concrete was established by using Weibull distribution function The reliability function of reinforcement in concrete. After the reinforcement is electrified to accelerate the test, the micro test analysis of the reinforcement is carried out. The results show that: with the increase of power on time, granular corrosion products appear on the surface of reinforced concrete in RC group, and a large number of micro cracks appear on the surface of reinforcement in rc-r group. The failure time of reinforcement with reliability of 60% is 880 h and 2060 h respectively. The service life of recycled concrete can be extended by 2.34 times.