气候变化对混凝土结构时变碳化寿命影响

Time-dependent carbonation life were researched for concrete remebers when climate changing

大气环境中碳化是混凝土结构使用寿命、耐久性主要影响因素。基于可靠度理论和2013年IPCC预测气候变化数据,结合中国混凝土结构耐久性设计规范要求,通过现有混凝土结构碳化预测模型,研究了混凝土结构碳化失效概率。结果表明:(1)RCP8.5、RCP6.0、RCP4.5、2015水平等情景对应的平均碳化深度、碳化寿命失效概率依次为RCP8.5>RCP6.0>RCP4.5>2015水平。(2)环境等级严酷性依次为I-A<I-B<I-C,而对应的平均碳化深度、碳化寿命失效概率却依次为I-A>I-B>I-C。(3)设计使用年限100年与50年混凝土碳化深度相比,未来气候变化对100年设计使用年限的混凝土结构碳化影响大。(4)凝土结构碳化寿命失效概率密度函数近似服从对数正态分布。研究成果对混凝土结构设计、剩余寿命预测、加固和维护具有参考作用。

Carbonization is one of the main factors affecting the using life and durability of reinforced concrete structures in atmospheric environment.According to IPCC forecast data of climate change in 2013 and the theory of reliability, basing on the code of concrete dura- bility design specification,a using the concrete carbonation time-dependent life prediction model,the failure probability of concrete time-dependent carbonation life were researched.The results of the study show that （ 1 ）The mean carbonation depth and the failure prob- ability of concrete structures were RCP8.5〉RCP6.0〉RCP4.5〉2015 level; （2）The environment class increased, but the mean carbonation depth and the failure probability of concrete structures decreased; （3）The future climate change would affect more for the concrete struc- ture of 100-year service life than 50-year service life; （4）The failure probability density function of the carbonation life for concrete struc- tures was approximate to log-normal distribution with time changing.The results would be useful for concrete structure design, mainte- nance, reinforcement and remaining life prediction.