外贴碳纤维布加固钢筋混凝土梁裂缝性能试验研究

通过外贴碳纤维(CFRP)布加固钢筋混凝土梁受弯试验,研究了加固后钢筋混凝土梁在不同CFRP用量、不同CFRP-混凝土粘结宽度和不同预裂裂缝情况下的弯曲裂缝性能,测量了加固梁中纯弯段内钢筋和CFRP应变分布,分析得到了CFRP-混凝土局部粘结-滑移曲线特征。结果表明,外贴CFRP对加固梁的裂缝性能具有显著的改善效果,随CFRP用量和CFRP-混凝土粘结宽度的增加,裂缝间距和宽度均减小,随预裂荷载的增大,加固梁的裂缝间距和宽度增大。采用基于粘结-滑移理论的裂缝分析模型对试验梁的裂缝性能进行了分析,模型同时考虑了钢筋-混凝土界面粘结-滑移和CFRP-混凝土界面粘结-滑移对裂缝性能的影响,模拟裂缝宽度和试验裂缝宽度的对比表明,基于粘结-滑移理论的裂缝分析是合理的。

A study on cracking behaviors of RC beams strengthened with external CFRP sheets

Flexural loading tests were carried out on RC beams strengthened with CFRP sheets.The influences of CFRP amount,CFRP width and the precracks on cracking behaviors were investigated,and the strain distributions of steel and CFRP in beams were documented for the different load levels.Through analyzing the measured data,the approximate bi-linear characters of interfacial local bond stress-slip relationship were concluded.The experimental results show that,due to the reinforcement by CFRP sheets,the cracking be...