BFRP筋混凝土短梁受剪承载力尺寸效应试验研究  

Experimental study on size effect of shear capacity of BFRP-reinforced concrete short beams

作　　者：宋博[1] 金浏[1] 张江兴 杜修力[1] SONG Bo;JIN Liu;ZHANG Jiangxing;DU Xiuli(The Key Laboratory of Urban Security and Disaster Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市减灾与防灾防护教育部重点实验室,北京100124

出　　处：《建筑结构学报》2024年第12期203-212,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51978022);北京市自然科学基金项目(JQ22025)。

摘　　要：合理配置受剪腹筋能有效削弱混凝土短梁的受剪承载力尺寸效应。对8根截面高度为300~1 200 mm的BFRP筋混凝土短梁(包括4根无腹筋短梁和4根水平、竖向腹筋率均为0.5%的短梁)开展了剪切试验。分析了破坏形态、荷载-位移曲线、腹筋应变等随梁截面高度变化的发展趋势,研究了无腹筋及含腹筋的BFRP筋混凝土短梁受剪承载力尺寸效应。结果表明:梁截面高度从300 mm增至1 200 mm时,无腹筋梁的截面名义抗剪强度下降52.3%,而腹筋率为0.5%短梁的截面名义抗剪强度下降45.7%,说明BFRP腹筋未能明显抑制短梁受剪承载力的尺寸效应;相比按照其他国家相关规范的受剪承载力计算结果,基于拉杆-拱模型的FRP筋混凝土短梁受剪承载力计算式可以较好地反映BFRP筋混凝土短梁的尺寸效应,其计算结果与试验结果吻合良好。The size effect of the shear capacity of concrete short beams can be effectively weaken by the reasonable arrangement of shear web reinforcement.Shear tests were conducted on eight BFRP-reinforced concrete short beams with cross-sectional heights of 300mm to 1200mm(including four short beams without web reinforcement and four short beams with horizontal and vertical web reinforcement ratios of 0.5%).The development trends of the failure mode,load-deflection curve,and web reinforcement strain with changes in beam section height were analyzed,and the size effect of shear capacity of BFRP-reinforced concrete short beams without and with web reinforcement was revealed.It is shown by tests that when the cross-sectional height increases from 300mm to 1200mm,the nominal shear strength of test beams without web reinforcement decreases by 52.3%,while the nominal shear strength of test beams with a web reinforcement ratio of 0.5%still decreases by 45.7%.The results indicate that BFRP-web reinforcement has not significantly suppressed the size effect behavior.Compared with the calculation results of relevant design codes in other countries,the shear capacity design method proposed by the author in previous research can reasonably reflect the size effect of BFRP-reinforced concrete short beams.The calculation results are in good agreement with the experimental results.

关 键 词：混凝土短梁 有腹筋梁 BFRP筋 受剪承载力 尺寸效应 

分 类 号：TU375.1[建筑科学—结构工程] TU317