U型ECC修复既有混凝土梁受剪性能研究  

Study on shear behavior of existing concrete beams repaired by U-shaped ECC

作　　者：李艳[1] 谢佳宁 刘泽军[1] 王昌野 朱永帅 Li Yan;Xie Jianing;Liu Zejun;Wang Changye;Zhu Yongshuai(School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454003,China)

机构地区：[1]河南理工大学土木工程学院,河南焦作454003

出　　处：《建筑科学》2023年第11期47-54,共8页Building Science

基　　金：国家自然科学基金(U1904188);河南省科技攻关项目(222102320431);河南省高校基本科研业务费专项资金资助项目(NSFRF220438)。

摘　　要：为研究ECC修复层厚度、剪跨比和损伤度等对修复梁受剪性能的影响,采用三点弯曲试验对U型ECC修复既有钢筋混凝土梁进行了受剪试验。试验结果表明:与对比梁相比,U型ECC修复梁的受剪承载力与变形能力明显提高,且修复层越厚,修复梁受剪性能的改善就越明显,而较大的U型修复层厚度还会使修复梁由剪切破坏转变为弯曲破坏;不同损伤度的既有钢筋混凝土梁经U型ECC修复后,其受剪性能也明显优于未修复的对比梁,且损伤度越小,修复梁的受剪性能就越好。基于“桁架-拱”理论模型,建立了ECC修复既有钢筋混凝土梁斜截面受剪承载力计算公式,结果表明公式的理论值与试验值吻合良好,可为后续ECC修复钢筋混凝土梁研究提供一定的理论参考。In order to study the effects of thickness of ECC repair layer,shear span ratio and damage degree on the shear behavior of repaired beams,three-point bending tests are carried out on existing reinforced concrete beams repaired by U-shaped ECC.The results show that the shear bearing capacity and deformation capacity of the beams repaired by the U-shaped ECC are significantly improved compared with those of the contrast beams,and the thicker the repaired layer is,the more obvious the improvement of the shear performance of the repaired beams will be.When increasing the thickness of the U-shaped repaired layer,the failure types of repaired beams may transform the shear damage into the bending damage.Furthermore,the smaller the damage degree is,the better the shear performance of the repaired beam will be.Based on the‘truss arch'theoretical model,a formula for calculating the shear capacity of inclined section of ECC repaired existing concrete beams is established.

关 键 词：ECC 修复 混凝土梁 受剪性能 

分 类 号：TU375[建筑科学—结构工程]