为研究受损钢筋混凝土梁采用粘贴钢板加固方法后承载力的变化,制作了2根混凝土梁试件.首先将试验梁加载开裂至正常损伤状态并测量对应的最大裂缝宽度,然后将其中一根梁按照规范设计方法进行加固处理,随后对试验梁进行抗弯承载力试验.在试验中通过采集应变、挠度和裂缝宽度等数据,综合评价钢板加固方法的效果.并通过比较各种材料应变随荷载的发展曲线,分析钢筋应变与钢板应变变化协同关系,验证平截面假定是否成立,最后通过各规范所提供的设计方法,将计算结果与试验结果进行对比分析.结果证明:粘贴钢板加固方法对提高受损钢筋混凝土梁的抗弯承载力具有显著效果,加固梁相对于未加固梁承载力提高58.2%;通过试验数据与规范计算结果的对比,可认为现有设计方法具有一定的安全性.研究内容和结果可以为规范公式的使用提供理论依据,也为实际工程钢板加固设计和施工提供参考.
To study the reinforcement effect and the flexural capacity changing of damaged concrete beams,two concrete beams were made.Firstly,they were bended to be cracked,then one of them was reinforced by steel plate according to standard.By the jack and reaction frame,two beams were tested to failure.During the tests,the strains of concrete,rebar and steel plate were recorded,as well as the crack and deformation of beams.Based on the test data,the strengthening effects were assessed comprehensively.Comparing the strain of rebars and steel plates,plane hypothesis was verified.Finally,the test results were compared with the values from various standards.From the research results,sticking steel plate can improve bearing capacity effectively by 50%,and the design methods in standards possess reasonable security.The research content and results can provide the theoretical basis for the using of design formulas,and they can be used as reference for the practical strengthening project.