多因素作用下混凝土梁长期性能时变劣化规律  

Time-varying deterioration of concrete beams under the action of multiple factors

作　　者：柏玉良 金伟良[1] 张怡雪 吴俊[1] 黄爽 朱明江 BAI Yuliang;JIN Weiliang;ZHANG Yixue;WU Jun;HUANG Shuang;ZHU Mingjiang(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058

出　　处：《交通科学与工程》2024年第4期65-75,共11页Journal of Transport Science and Engineering

基　　金：国家自然科学基金资助项目(51638013,51820105012,52178176)。

摘　　要：为了探究混凝土梁在锈蚀、疲劳、徐变等多因素长期作用下的性能劣化规律,对21根试验梁开展了锈蚀、疲劳和徐变的正交分组试验,通过对钢筋锈蚀深度、梁的刚度和疲劳寿命的测量计算,研究了钢筋混凝土梁长期性能的时变劣化规律。研究结果表明:相较于无损梁,在2.5%、15.0%、60.0%疲劳寿命比和3、6个月持续荷载作用下,损伤混凝土梁的锈蚀深度扩大了1.337~1.934倍;随着钢筋锈蚀和疲劳损伤程度的加深,损伤梁的刚度下降了1.694 kN·m^(2),在持续荷载作用下,其刚度仅为无损梁的34.1%;在锈蚀和徐变相继作用后,损伤梁的疲劳寿命仅为无损梁的16.14%。根据试验研究结果,给出了损伤混凝土梁的临界锈蚀深度衰减系数、短期刚度降低系数、刚度退化系数和疲劳寿命衰减系数,以反映复杂荷载与环境作用对混凝土梁长期性能的影响,为混凝土结构的长期性能评估提供了科学依据。In order to investigate the performance degradation law of concrete beams under the longterm influence of multiple factors such as corrosion,fatigue,and creep,orthogonal grouping experiments involving corrosion,fatigue,and creep were conducted on 21 test beams.Measurements and calculations were performed on the corrosion depth of the steel reinforcement,the stiffness of the beams,and their fatigue life.The research results indicate that,compared to undamaged beams,the corrosion depth in damaged concrete beams increases by 1.337 to 1.934 times under 2.5%,15.0%and 60.0%fatigue life ratios and 3 and 6 months of sustained loading.As the degree of reinforcement corrosion and fatigue damage deepens,the stiffness of the damaged beams decreases by 1.694 kN·m^(2),and under sustained loading,their stiffness is only 34.1%of that of the undamaged beams.After the combined effects of corrosion and creep,the fatigue life of the damaged beams is reduced to only 16.14%of that of the undamaged beams.Based on the experimental results,critical corrosion depth attenuation coefficients,short-term stiffness reduction coefficients,stiffness degradation coefficients,and fatigue life attenuation coefficients for damaged concrete beams are provided,reflecting the impact of complex loading and environmental factors on the long-term performance of concrete beams.These findings offer a scientific basis for the long-term performance assessment of concrete structures.

关 键 词：多因素作用 混凝土梁 临界锈蚀深度 短期刚度 疲劳寿命 长期性能 

分 类 号：TU375.1[建筑科学—结构工程]