高强钢绞线网-聚合物砂浆抗剪加固梁刚度及裂缝分析  

Analysis of stiffness and cracks of shear strengthened beam with stainless steel wire mesh and polymer mortar

作　　者：黄华[1,2] 刘伯权[1] 吴涛[1] 

机构地区：[1]长安大学建筑工程学院,陕西西安710061 [2]长安大学旧桥检测与加固技术交通行业重点实验室,陕西西安710064

出　　处：《土木工程学报》2011年第3期32-38,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(50608004);高等学校博士点基金(20090205120008);中央高校科研专项基金(CHD2009JC160);长安大学基础研究专项基金

摘　　要：对高强不锈钢绞线网-渗透性聚合物砂浆加固的9根矩形钢筋混凝土梁进行抗剪试验研究,分析加固方式、固定钢绞线网的螺栓数量、间距、二次受力等因素对加固构件刚度和裂缝的影响。研究结果表明:该加固工艺能够显著提高混凝土梁的刚度,延迟斜裂缝的出现,减小斜裂缝宽度;多而密的固定螺栓会对原梁刚度造成极大削弱;U形加固直接在梁顶产生层间裂缝而发展为加固层剥离,环包加固却在梁上下边缘处形成水平临界裂缝,而后发展为加固层剥离破坏;持载程度高的梁刚度提高幅度小,斜裂缝发展快,但修复破坏梁效果显著;在试验研究和理论分析基础上,提出考虑剪切变形的加固梁挠度计算公式和斜裂缝宽度计算公式。Experiments were conducted to investigate the shear behavior of nine RC rectangular beams strengthened with stainless steel wire mesh and permeability polymer mortar.The influences on the stiffness and cracks were discussed,including strengthening mode,bolt amount,bolt distance,and secondary load.The test results show that the rehabilitation can greatly increase the beam stiffness,reduce the width of diagonal cracks,and postpone the occurrence of diagonal cracks.Too many or too dense bolts would badly weaken the stiffness of the beam.Internal fractures occurred on the top of the beam strengthened with U-shape and may develop debonding failure,but horizontal critical cracks formed on the top and bottom of the beam strengthened at four sides and may also develop debonding failure.The range of increase of the beam stiffness is lower and the development of diagonal cracks is faster if the secondary load is larger.The rehabilitation effects on the beams are remarkable.Based on the experiments and theoretical analysis,the methods for calculation of the deflection and the width of diagonal cracks are proposed.

关 键 词：高强钢绞线网 聚合物砂浆 抗剪加固 刚度 斜裂缝 试验研究 

分 类 号：TU376[建筑科学—结构工程]