采用背对背加载方式,利用螺杆对钢筋混凝土受弯构件施加持续荷载,进行氯盐溶液侵蚀与加速碳化交替作用试验,基于半电池电位法和线性极化法研究了混凝土在碳化、氯盐侵蚀与荷载三者共同作用下的钢筋锈蚀规律。试验结果表明,干湿循环导致钢筋锈蚀速率增长;荷载水平较低时,碳化对钢筋锈蚀的影响占主导作用;荷载水平较高时,需综合考虑碳化与荷载作用的影响。双掺矿粉和粉煤灰的混凝土钢筋锈蚀速率较普通混凝土快。腐蚀电流密度在0.1~1μAcm2之间时,对应腐蚀电位在-200~-350 m V之间,基于半电池电位法判断钢筋的锈蚀状态具有一定的局限性,辅以线性极化法可以对钢筋锈蚀状态进行定量分析。
Sustained load was applied on reinforced concrete beams with screws by the way of back-to-back loading.Then the alternated test with chloride ingress and carbonation process was conducted. The rebar corrosion law in reinforced concrete, under the combined effect of carbonation, chloride and loading, was studied by half-cell potential method and linear polarization method. The test results indi- cate that drying-wetting cycle's effect increase the rebar corrosion rate. The carbonation factor is dominant in rebar corrosion process with low load level. However, both carbonation and load should be taken into account if the load level is high. Rebar corrosion rate with double-mixture concrete is higher than ordinary concrete.There are some limitations using half-cell potential method when corrosion po- tential is between - 200 mV to - 350 mV, which corresponds to 0.1 μA/cm2 to 1 μA/cm2 corrosion current density, thus linear polariza- tion method can be used to quantitative analyze the rebar corrosion condition.