摘要
对海洋环境下服役26年的3根钢筋混凝土梁开展受弯试验研究,获得荷载—变形全过程曲线,以评估自然锈蚀钢筋混凝土梁的受力性能。加载试验后,利用3D激光扫描技术获取了锈蚀钢筋横截面积的纵向分布。在此基础上,对自然锈蚀钢筋混凝土梁的受弯破坏模式、裂缝发展、承载力及截面应变发展进行分析。结果表明:自然环境下钢筋的锈蚀沿纵向呈明显的不均匀性,总体呈现跨中锈蚀严重、两端锈蚀轻的规律,与箍筋接触位置的纵筋因受到箍筋的保护而与相邻位置相比锈蚀程度更轻。自然锈蚀钢筋混凝土梁的破坏模式与未锈蚀适筋梁类似,但破坏截面处纵筋间锈蚀差异大,导致严重锈蚀钢筋可能先断裂,引发应力重分布,荷载—挠度曲线表现出“多阶段”特征。锈蚀最严重试件的屈服和极限荷载相较锈蚀最轻试件分别下降了18.1%和14.7%;基于破坏模式的锈蚀钢筋混凝土梁正截面受弯承载力计算结果与试验结果吻合良好。
To evaluate the mechanical performance of naturally corroded reinforced concrete(RC)beams,bending tests were conducted on three RC beams that had been in service for 26 years in a marine environment,and the load-deformation full-process curves were obtained.Following the tests,the distribution of the cross-sectional area of corroded rebars along the longitudinal direction of the beams was captured employing 3D laser scanning technology.Based on this data,an analysis was performed on the bending failure modes,crack development,load-bearing capacity,and strain development of naturally corroded RC beams.The results indicate that the reinforcement corrosion in natural environments exhibits significant non-uniformity along the longitudinal direction,generally following a pattern of more severe corrosion at mid-span and less severe corrosion towards the ends.Moreover,longitudinal rebars in contact with stirrups exhibit reduced corrosion compared to adjacent positions,due to the protective effect of the stirrups.The failure mode of naturally corroded RC beams resembles that of uncorroded under-reinforced beams.However,substantial differences in corrosion degree among longitudinal rebars at the failure cross-section can lead to premature fracture of severely corroded rebars,causing redistribution of stress,which manifests as a“multi-stage”characteristic in the load-deflection curves.Compared with the least corroded specimen,the yield and ultimate loads of the most severely corroded specimen decreases by 18.1%and 14.7%,respectively.Additionally,the bending bearing capacity of the corroded RC beams,calculated by using the failure mode-based method,shows good agreement with the experimental results.
作者
刘阳
张伟平
姜超
邱俊澧
王瑞琳
郑乃浩
LIU Yang;ZHANG Weiping;JIANG Chao;QIU Junli;WANG Ruilin;ZHENG Naihao(Key Laboratory of Performance Evolution and Control for Engineering Structures of the Ministry of Education,Tongji University,Shanghai 200092,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)
出处
《同济大学学报(自然科学版)》
北大核心
2025年第8期1181-1191,共11页
Journal of Tongji University:Natural Science
基金
国家自然科学基金(52361135809)
上海市社会发展科技攻关项目(22dz1203603)。
关键词
钢筋混凝土梁
自然锈蚀
静力试验
受弯承载力
海洋环境
reinforced concrete(RC)beams
natural corrosion
static test
bending bearing capacity
marine environment
作者简介
第一作者:刘阳,博士生,主要研究方向为混凝土结构性能演化。E-mail:liu49@tongji.edu.cn;通信作者:姜超,副教授,工学博士,主要研究方向为混凝土结构性能演化与控制。E-mail:cjiang@tongji.edu.cn。
