应力损伤对混凝土抗碳化性能的影响

Influence of Stress Damage on Carbonation of Concrete

应用超声波波速来定义混凝土的损伤度,采用混凝土快速碳化试验方法研究了基准混凝土及损伤度为0.05,0.12,0.19,0.27的应力损伤混凝土的抗碳化性能.结果表明:应力损伤混凝土的碳化规律与基准混凝土相似,其碳化深度随时间的变化亦符合指数形式;混凝土的碳化深度随损伤度的增加而增大.为定量分析应力损伤的影响程度,定义损伤影响因子KD来描述应力损伤对混凝土抗碳化性能的影响,KD与损伤度D呈线性关系.通过对混凝土碳化耐久性的分析发现,应力损伤对混凝土碳化寿命影响较大,当损伤度D达到0.27时,其碳化寿命仅为基准混凝土的0.39.

Damage degree of concrete was defined by th~ ultrasonic wave velocity. The carbonation resistance of control concrete and the concrete with different stress damage degrees of 0.05, 0.12, 0.19, 0.27, was studied by the accelerated carbonation test method. The results show that the basic carbonation regularity of stress damaged concrete is similar to that of control concrete. The carbonation depth also obeys the exponential function of time and increases with stress damage degree. The damage impact factor KD was put forward to quantify the effect of initial stress damage on the carbonation characteristic of concrete. A linear relationship exists between the impact factor KD and damage degree D. Also, with the analysis of carbonation durability of damaged concrete, the stress damage has a significant effect on it, and the relative carbonation service life is 0.39 times that of control concrete when the damage degree is 0.27.