荷载和氯盐环境下RC梁非均匀锈蚀与承载力劣化试验  

Non-uniform Corrosion and Load Bearing Capacity Deterioration Tests of Reinforced Concrete Beams Under Load and Chloride Salt Environment

作　　者：赖骏 蔡健[1,2] 左志亮[1] 冯怿年 LAI Jun;CAI Jian;ZUO Zhiliang;FENG Yinian(School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510641,China;State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]华南理工大学土木与交通学院,广东广州510641 [2]华南理工大学亚热带建筑科学国家重点实验室,广东广州510641

出　　处：《西南交通大学学报》2024年第5期1140-1147,1157,共9页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金项目(51578246)。

摘　　要：为考察持续荷载与氯盐干湿循环共同作用对钢筋混凝土(RC)梁抗弯性能的影响,先后进行19根钢筋混凝土梁的腐蚀试验和抗弯承载力试验,研究不同持续荷载等级和干湿循环天数对裂缝分布、钢筋质量锈蚀率以及受腐蚀构件受弯性能的影响,并分别总结纵筋最大和平均质量锈蚀率与承载力降低比的关系.研究结果表明:纯弯段的钢筋锈蚀程度较高,纵筋锈蚀程度沿圆周分布不均匀;纵筋质量锈蚀率的极值点位置与初始横向裂缝的出现位置无必然关联性;纵筋最大质量锈蚀率随荷载等级和干湿循环天数的增加而增大,受干湿循环天数的影响更明显;腐蚀后梁峰值荷载呈下降趋势;当纵筋锈蚀率较小时(平均值≤3%或最大值≤6%),锈蚀率与承载力降低比的相关度较低,且最大质量锈蚀率的相关度小于平均质量锈蚀率;当纵筋锈蚀率较大时(平均值>3%或最大值>6%),质量锈蚀率与承载力降低比的相关度提高;在纵筋平均质量锈蚀率相同时,采用自然腐蚀试件的承载力降低程度高于采用外加电流腐蚀的试件.To explore how sustained loading and drying-wetting cycles of chloride salt affect the flexural behavior of reinforced concrete(RC) beams,the corrosion tests and flexural capacity tests of 19 RC beams were carried out at first.The effects of various sustained loading grades and drying-wetting cycle periods were studied on the crack distribution,the mass corrosion rate of longitudinal reinforcements,and the flexural behavior of corroded members.The relationship was summarized between the maximum and average mass corrosion rate of longitudinal reinforcements and the flexural bearing capacity reduction ratio.The study results show that the corrosion degree of longitudinal reinforcements was higher in the pure bending segment than in other areas,and distributed non-uniformly along the circumference of the longitudinal reinforcements.There was no noticeable correlation between the position of the extreme mass corrosion rate of longitudinal reinforcements and the occurrence position of initial transverse cracks.The maximum mass corrosion rate of longitudinal reinforcements increased with the loading grade and drying-wetting cycle period,and was more notably affected by the dryingwetting cycle period.The peak load of the beam decreased after corrosion.When the mass corrosion rate of the longitudinal reinforcements was low(average value below 3% or maximum value above 6%),the correlation between the mass corrosion rate and the reduction ratio of bearing capacity was low,and the maximum mass corrosion rate has less correlation with the reduction ratio of bearing capacity than the average mass corrosion rate.When the mass corrosion rate of longitudinal reinforcements increased(average value above 3% or maximum value above 6%),both the maximum and the average mass corrosion rates of longitudinal reinforcements had an increased correlation with the reduction ratio of bearing capacity.When the average mass corrosion rate of longitudinal reinforcements is the same,the reduction of bearing capacity of specimens with natural cor

关 键 词：钢筋混凝土 干湿循环 持续荷载 钢筋锈蚀 承载力降低比 

分 类 号：TU375.1[建筑科学—结构工程]