HRB500级钢筋混凝土框架梁开裂性能试验研究  

Experimental research on cracks of HRB500 steel reinforced concrete frame beams

作　　者：易伟建[1] 余东[1] 江涛 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南省建筑设计院,湖南长沙410011

出　　处：《建筑结构学报》2013年第1期147-154,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51078133)

摘　　要：为了研究HRB500级钢筋作为受力主筋的混凝土框架梁开裂性能,对3榀1层2跨的混凝土框架结构进行静力试验,量测了在跨中集中荷载作用下梁端与跨中截面的裂缝宽度、位移、转角以及混凝土和钢筋应变。结果表明:框架梁端裂缝宽度实测值一般大于采用现行混凝土结构设计规范公式的计算值。研究了框架梁端裂缝的开展机理,基于黏结-滑移理论,提出把裂缝处钢筋与混凝土之间的滑移分为在节点内滑移和在梁端内滑移两部分,建立框架梁抵抗负弯矩的纵向钢筋在节点区的黏结-滑移模型和相应的最大裂缝宽度计算式,并根据对试验结果的统计分析,校准了黏结-滑移模型的参数。框架梁端最大负弯矩作用下的裂缝宽度计算式可供工程实践和规范修订参考。In order to study the performance of concrete frame beams reinforced with HRB500 steel bars,three single story,two-bay concrete frames were tested under static loading.During testing the displacements,rotation angles,cracks,and strains of concrete and steel of the beam were measured under mid-span loading.It is shown by calculation that in serviceability limit state,the maximum measured crack width at the mid-span of the frame beam is generally smaller than that calculated according to the Chinese design code,while the crack width measured at the beam end is larger than that calculated according to the code.The mechanism of the crack at the beam end was analyzed.On the basis of bond-slip theory the slip between longitudinal steel bar and concrete was divided into two parts： slip in the beam-column joint and in end region of the beam.Then the slip model of tension steel bar in the negative bending moment region and the formula of maximum crack width were developed.Based on the statistic analysis of test results the parameters in the model were calibrated.The proposed formula of crack width of the frame beam under maximum negative bending moment can be used in engineering practice and as a reference for the modification of the code.

关 键 词：混凝土框架梁 HRB500级钢筋 静力试验 框架梁端裂缝 

分 类 号：TU375.1[建筑科学—结构工程] TU317.1