CO_2排放、气候变化及其对混凝土结构开始腐蚀时间和时变可靠度评估的影响  

CO_2 Emission,Climate Change and Their Effects on Corrosion Initiation Time and Time-dependent Reliability of Concrete Structures

作　　者：彭建新[1,2] 邵旭东[1] 

机构地区：[1]湖南大学桥梁工程研究所,湖南长沙410082 [2]长沙理工大学土木与建筑学院,湖南长沙410014

出　　处：《公路交通科技》2009年第10期76-81,86,共7页Journal of Highway and Transportation Research and Development

基　　金：湖南省交通厅科技项目(200614);湖南省应用基础重点项目(06FJ008)

摘　　要：基于改进的碳化深度预测模型,结合IPCC预测数据,研究了气候变化（CO2浓度）的规律及其对混凝土结构的碳化损伤影响。由于概率预测模型能够考虑环境、结构尺寸、保护层厚度和劣化机制的不确定性和变异性,提出了时变可靠度模型来计算混凝土结构在多种CO2排放策略作用下将来100年内的开始腐蚀概率。研究表明：在最高CO2排放策略下的开始腐蚀概率比其在最好CO2排放策略下高4.6倍;大多数混凝土结构在服役期存在碳化腐蚀损伤现象,将来需要大量的维修和维护工作;如果最高CO2排放策略在将来发生,混凝土保护层设计厚度需要提高3～15 mm以降低混凝土结构的开始腐蚀概率和减少腐蚀损伤。Based on the corrected carbonation depth prediction model, the increases of CO2 level with predicted climate change and its effect on carbonation-induced damage to concrete structures were studied by using information of climate change provided by IPCC. Probabilistic methods were used as the significant uncertainty and variability of deterioration mechanism, material properties, structural dimensions and environment. The time-dependent structural reliability analysis model was proposed to calculate the probability of corrosion initiation of concrete structure under several IPCC atmospheric CO2 emission scenarios over the next 100 years.The results show that （1） for the worst case emission scenario the probability of corrosion initiation is 4.6 times higher than that for the best mitigation scenario; （2） there is a significant likelihood of corrosion damage that will need costly and disruptive repairs during the service life of many concrete structures; （3） if the worst emissions scenario would be viewed as the most likely scenario then increasing design cover by approximately 3 - 15 mm should be needed to ameliorate the probability of corrosion initiation and corrosion damage.

关 键 词：桥梁工程 气候变化 混凝土 碳化 腐蚀 结构可靠度 

分 类 号：TU311.4[建筑科学—结构工程]