锈蚀疲劳耦合作用下钢筋混凝土梁性能退化试验  

Experimental study on performance degradation of reinforced concrete beams under coupled effect of corrosion and fatigue

作　　者：马亚飞 齐洪鹤 苏小超 汪国栋 王磊 张建仁 MA Ya-fei;QI Hong-he;SU Xiao-chao;WANG Guo-dong;WANG Lei;ZHANG Jian-ren(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114

出　　处：《实验力学》2020年第3期472-478,共7页Journal of Experimental Mechanics

基　　金：国家自然科学基金项目(51508036);国家重点基础研究发展计划(973计划)项目(2015CB057705);湖南省教育厅科学研究项目(17B012);长沙市科技计划项目(kq1802012)。

摘　　要：锈蚀疲劳的耦合作用会显著降低钢筋混凝土结构的使用寿命。为模拟锈蚀疲劳耦合作用对钢筋混凝土构件抗弯性能的影响,开展了三组不同情况下钢筋混凝土梁的疲劳试验:预先锈蚀后疲劳试验、盐溶液环境中疲劳试验和盐溶液通电环境中疲劳试验。研究了钢筋混凝土梁在疲劳荷载下的荷载-挠度关系、混凝土裂缝的发展规律,对比了不同试验环境下钢筋混凝土梁的疲劳寿命及破坏形态。试验结果表明,疲劳荷载下混凝土裂缝发展规律与环境相关,盐溶液中梁混凝土斜裂缝水平倾角较小,盐溶液通电梁混凝土裂缝扩展高度明显增大;锈蚀疲劳耦合作用加速了钢筋的疲劳裂纹扩展速率,使得混凝土疲劳模量下降,导致梁的刚度退化,疲劳寿命显著降低,且腐蚀环境作用越强,影响越显著;三种试验环境下钢筋混凝土梁的破坏形式未发生改变,均为主筋发生疲劳脆性断裂,在疲劳寿命简化分析中可将受力钢筋作为研究主体。本试验是对已有预锈蚀梁疲劳试验的补充和延伸,可为日后混凝土桥梁的腐蚀疲劳耦合作用建模提供试验基础。The coupled effect of corrosion and fatigue significantly decreases the service life of reinforced concrete structures.To simulate the coupled effect of corrosion and fatigue on the flexural behavior of reinforced concrete samples,three groups of fatigue tests of reinforced concrete beams are conducted,including the pre-corrosion fatigue test,the fatigue test in salt solution environment,and the fatigue test in electrified salt solution environment.The load-deflection relationship and the development of concrete crack propagation under fatigue loads are investigated.The fatigue life and failure modes of reinforced concrete beams under different test environments are compared.The experimental results show that the development of concrete crack under fatigue loads is related to the environment.The horizontal inclination angle of concrete cracks in salt solution is small,while the crack propagation height in electrified salt solution obviously increases.The coupled effect of corrosion and fatigue accelerates the fatigue crack propagation rate of steel bar and decreases the fatigue modulus of concrete,resulting in a reduction in the stiffness and fatigue life of reinforced beams.The stronger the corrosive environment is,the more significant the effect is.The failure mode is not changed in three cases,and all the beams have a brittle failure as fatigue fracture of steel bars under different test environments.The steel bars can be considered as the main failure mechanism in the simplified fatigue life prediction analysis.This study is an important supplement and extension to the existing fatigue tests of pre-corroded beams,which provides an experimental basis for the coupled corrosion fatigue modelling for concrete bridges.

关 键 词：桥梁工程 钢筋混凝土 腐蚀环境 疲劳 刚度 

分 类 号：TU375.1[建筑科学—结构工程] U447[建筑科学—桥梁与隧道工程]