中文摘要：

目的研究杂散电流、氯盐及其共存环境下钢筋混凝土的疲劳损伤演变规律.方法将钢筋混凝土试件置入不同质量浓度的NaCl溶液中,进行4点弯曲疲劳试验的同时,施加不同强度的杂散电流.试件损伤破坏过程中,用超声波实时监测试件的声速变化.结果超声波法可有效跟踪腐蚀环境条件下钢筋混凝土的疲劳损伤发展.钢筋混凝土在杂散电流、氯盐及其共存环境下的疲劳损伤发展,与在一般大气环境下的疲劳损伤发展类似,可分为缓慢累积和快速累积2个阶段,但损伤发展速率不同.杂散电流强度越大,氯盐质量浓度越大,试件疲劳损伤发展越快.结论杂散电流和氯盐对地铁钢筋混凝土的疲劳损伤发展存在很大影响,建立了杂散电流和氯离子共存下钢筋混凝土的疲劳损伤演化方程,可为研究地铁钢筋混凝土的损伤劣化机理分析提供试验和理论基础.

英文摘要：

The fatigue damage development laws of the reinforced concrete（RC）in the different corrosive environments such as stray current,chloride,stray current and chloride coexistence were investigated.The ultrasonic velocity change of the RC specimens after previously soaked in NaCl solution with different concentration,which were applied to the coupling load of four-point-bending fatigue and stray current at the same time,were real-time monitored.The results show that the ultrasonic method can effectively monitor the fatigue damage process of the RC in corrosive environments.The bending fatigue damage process of the RC specimens in the different corrosive environments such as stray current,chloride,stray current and chloride coexistence is similar to that of the RC specimens exposed to the air,having two stages such as stably increasing stage and rapidly increasing stage.However,the level of damage development is different.The fatigue damage of specimens develops faster with the increase of stray current intensity and chloride concentration.So the stray current and chloride has a great influence for the fatigue damage development of subway concrete.The fatigue damage development equation of the RC in stray current and chloride coexisted environment was established which can provide experimental and theoretical foundation for the further research about damage mechanism analysis of subway reinforced concrete.