钢筋锈胀下混凝土抗压强度退化试验研究

Experimental Study of Compressive Strength Degradation of Concrete Under Steel Bars Rusting and Swelling

为了研究电流作用下钢筋锈胀对混凝土抗压强度的影响,采用外加直流电方法制备锈胀混凝土试件,对比分析了不同电流强度腐蚀下混凝土的开裂过程、破坏形态,并研究了在混凝土内部钢筋锈蚀情况下,混凝土抗压强度的变化规律。结果表明:在钢筋通电加速锈蚀情况下,埋有钢筋的混凝土试件抗压强度退化历程可分为三阶段;电流强度越大,混凝土抗压强度开始降低的初始时间越早。最后根据试验数据,提出了钢筋锈胀混凝土抗压强度时变退化模型,经过验证分析,证明了该模型的有效性。

In order to study the effect of steel bars rusting and swelling on compressive strength of concrete under current action,the adding of direct current was adopted to prepare rusted expansive concrete specimens,the cracking process and failure pattern of concrete under different current intensity corrosion were comparatively analyzed,and the change law of the compressive strength of concrete under the condition of rusted steel bars inside concrete was studied.The results showed that under the condition that steel bars are accelerating corrosion,the compressive strength degradation process of the reinforced concrete specimens could be divided into three stages;furthermore,with the increase of current intensity,the initial time when concrete strength begins to decrease becomes earlier;finally,according to the test data,a time-varying degradation model of reinforced concrete with corroded expansion was proposed,which proved the validity of the model after verification and analysis.