外贴碳纤维布加固钢筋混凝土梁裂缝性能试验研究  

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

作　　者：曹双寅[1] 蔺新艳[1,2] 敬登虎[1] 黄凤霞[1] 王艳芳[1] 

机构地区：[1]东南大学土木工程学院,江苏南京210096 [2]河南理工大学土木工程学院,河南焦作454000

出　　处：《建筑结构学报》2010年第1期33-40,共8页Journal of Building Structures

基　　金：江苏省自然科学基金项目(BK2007567)

摘　　要：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。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 behaviors of RC beams are obviously enhanced. The crack spacing and width in beams diminish when the CFRP amount or CFRP width increases, however those become large with the increase of preload. A theoretical nonlinear model derived from a cracking analysis, based on slip and bond stresses, is adopted to simulate the cracking behaviors of tested beams. The model allows considering the bond-slip relationships both between concrete and steel bar and between concrete and CFRP. Comparisons between the simulated crack width and that of experiment indicate that the approach for cracking analysis founded on bond-slip theory is effective and appropriate.

关 键 词：钢筋混凝土梁 碳纤维布 静力试验 预裂荷载 裂缝 粘结-滑移关系 

分 类 号：TU375.12[建筑科学—结构工程] TU317.1