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使用大气气候变化数据,改进了氯离子作用下腐蚀开始时间模型和腐蚀电流密度模型,分析了全球变暖(CO2浓度和温度)对RC桥梁在氯离子腐蚀作用下的锈胀开裂性能影响。考虑腐蚀影响的性能预测参数如气候变化、氯离子浓度、氯离子扩散过程、温度、湿度、结构尺寸参数、钢筋位置和性能退化机制等具有随机性和时变性,发展了基于时变可靠度理论的预测方法来预测RC桥梁在将来全球变暖作用下以及氯盐环境下将来服役100年内的开始腐蚀风险和平均锈胀开裂概率。研究发现:1)在预测氯离子腐蚀效应时,大气气候变化温室效应能够恶化混凝土腐蚀损伤效应,在预测时需要计入其效应;2)在浪溅区环境下的开始腐蚀概率和锈胀开裂比例比海岸线大气区环境下分别高了127%和140%,当结构位于距离海岸线1km以上区域时锈胀开裂比例降低到1%;3)对于保护层厚度为20mm和水灰比为0.55的混凝土,在将来100年内的开裂概率为0.893,这意味着大多数混凝土结构在服役期存在腐蚀损伤现象,将来需要大量的维修和维护工作。这些信息能够为决策人员应对温室效应和氯离子腐蚀对土木工程的影响做出应对措施提供支持。
Using the data of atmospheric climate change, the model of corrosion initiation time and the model of corrosion current density were improved. The effects of global warming (CO2 concentration and temperature) on corrosion and corrosion cracking of RC bridges under chloride ion corrosion were analyzed. Due to the stochastic and time-varying nature of the performance prediction parameters such as climate change, chloride ion concentration, chloride ion diffusion process, temperature, humidity, structural size parameters, reinforcement location and performance degradation mechanism considering the influence of corrosion, Prediction method to predict the RC corrosion risk and the average probability of rust cracking in future 100 years of service under the effect of global warming and in the chloride salt environment. The results show that: 1) When predicting the chloride ion corrosion effect, the greenhouse effect of atmospheric climate change can deteriorate the corrosion damage effect of concrete, and its effect should be taken into account in the prediction; 2) The probability of initial corrosion and rust cracking in the splash zone The proportion is 127% and 140% higher than that of the coastline atmospheric environment respectively, and the proportion of rust expansion and cracking is reduced to 1% when the structure is located more than 1km away from the coastline. 3) For the concrete with the protective layer thickness of 20mm and the water-cement ratio of 0.55 , With a probability of cracking of 0.893 in the next 100 years, which means that most concrete structures exhibit corrosion damage during service and require extensive repair and maintenance work in the future. This information can support decision makers in responding to the greenhouse effect and the impact of chloride ion corrosion on civil engineering.