气候变化对中国钢筋混凝土基础设施碳化腐蚀及破坏风险的影响

Climate change effects on carbonation-induced corrosion and damage risks of RC infrastructure in China

气候变化会使大气中CO2浓度和温度升高,改变相对湿度,因此会改变混凝土基础设施的周围环境。尤其在气候变化的长期作用下,混凝土结构的安全性、适用性和耐久性都会加速衰减。文中描述在气候变化影响下,两个典型城市厦门和韶关的混凝土基础设施在2010~2100年间的碳化损伤研究。两城市大气CO2浓度、温度和相对湿度的预测均基于代表性浓度途径(RCPs)。采用蒙特卡洛模拟进行时效分析,考虑结构尺寸、材料特性、气候预测和预测模型的不确定性。混凝土结构的腐蚀破坏风险由保护层严重开裂的概率表示。结果表明,至2100年气候变化可使平均碳化深度增加达8mm;同时也可造成温热地区的混凝土建筑物的碳化腐蚀破坏概率增加12%~19%。此研究可为将来气候变化对土木设施的影响和气候适应策略提供参考依据。

Climate change may increase atmospheric CO2 concentration and temperature,change relative humidity(RH),and consequently change RC infrastructures' surrounding environment. Especially in the long run,the decline of the safety,serviceability and durability of RC structures may be accelerated. Carbonation induced corrosion damage of RC infrastructure in Xiamen and Shaoguan under a changing climate is investigated for time period 2010 ~ 2100. The projection of atmospheric CO2 concentration,temperature and RH in both cities are based on the representative concentration pathways(RCPs). The time-dependent reliability analysis was conducted by Monte Carlo simulation and includes the uncertainty of dimensions,material properties,climate projections,and predictive models. The corrosion damage risks of RC structures are represented by the probability of severe cracking of concrete cover. Results show that climate change may increase mean carbonation depth by 8mm by 2100. Moreover,carbonation-induced damage risk for RC buildings in temperate areas can be increased by 12% ~ 19%. This research provides a reference for impacts of future climate change on RC structures and development of climate adaptation strategies.