不同配筋率下钢筋混凝土板柱节点抗冲切承载力试验研究

EXPERIMENTAL STUDY ON THE PUNCHING AND SHEARING RESISTANCE OF REINFORCED CONCRETE SLAB-COLUMN JOINTS WITH DIFFERENT REINFORCEMENT RATIOS

为研究纵筋配筋率对普通钢筋混凝土板柱节点抗冲切承载力的影响,制作了4个配筋率分别为0.3%、0.7%、1.2%及1.8%的无腹筋板柱中节点并进行冲切试验,试验结果表明:随着配筋率的增加,板柱节点的初始刚度和极限承载力明显增加,试件的延性降低,破坏模式由弯曲破坏逐渐向冲切破坏转变;收集并整理了国内外269个板柱节点冲切试验的数据,通过与采用中国规范、美国规范、欧洲规范和日本规范抗冲切承载力计算公式计算结果的对比分析,进一步说明了在冲切承载力计算公式中考虑纵筋配筋率的必要性;通过对试验数据的回归分析,考虑包含纵筋配筋率在内的主要影响因素,建立了适用于钢筋混凝土无腹筋板柱抗冲切承载力的计算公式。

In order to study the effect of longitudinal reinforcement ratio on the punching shear capacity of ordinary reinforced concrete slab-column connections,four slab-column interior connections with reinforcement ratios of 0.3%,0.7%,1.2%and 1.8%were made without stirrups,and punching shear tests were conducted.The test results show that with the increase of reinforcement ratio,the initial stiffness and ultimate capacity of slab-column connections increase significantly,while the ductility of specimens decreases.The damage mode changes from bending failure to punching failure gradually.The data of 269 punching shear tests on slab-column connections from both domestic and international sources were collected and organized,and then a comparative analysis was performed using codes from China,American,Europe,and Japan for punching shear capacity,which further emphasized the necessity of considering the longitudinal reinforcement ratio in the formulas.Through regression analysis of the experimental data and considering the major influencing factors,including the longitudinal reinforcement ratio,a calculation formula applicable to the punching shear capacity of reinforced non-stirrup concrete slab-columns was proposed.