BFRP筋及钢筋混凝土深梁剪切破坏尺寸效应对比分析  

Comparison of size effect in shear failure of BFRP and steel-reinforced concrete deep beams

作　　者：金浏[1] 雷宇霜 杜修力[1] Jin Liu;Lei Yushuang;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：《土木工程学报》2022年第8期55-66,共12页China Civil Engineering Journal

基　　金：国家重点研发计划(2018YFC1504302);国家自然科学基金(51822801)。

摘　　要：为探究BFRP筋和钢筋混凝土深梁剪切性能及尺寸效应之间的异同,借助三维细观数值方法,进行BFRP筋及钢筋混凝土深梁静态剪切破坏数值试验。结合现有试验,在验证该模拟方法合理性和准确性的基础上,分析截面高度、剪跨比和配筋类型(BFRP筋和钢筋)对深梁剪切破坏行为及相应尺寸效应规律的影响。另外,将模拟结果与各国规范及Jin等提出的尺寸效应律进行对比分析。研究表明:①BFRP筋混凝土深梁的剪切尺寸效应比钢筋混凝土深梁的更明显,即BFRP筋混凝土深梁的抗剪承载力及延性随梁尺寸增加的下降程度比钢筋混凝土深梁的更多;②剪跨比对梁剪切强度有显著的影响,但其对梁剪切尺寸效应基本没有影响;③对于大尺寸梁的抗剪承载力,各国规范的计算结果安全储备不足,且各国关于FRP筋梁的规范缺少对剪跨比影响的考虑;④Jin等所提的尺寸效应律同样适用于BFRP筋和钢筋混凝土深梁。In order to explore the similarities and differences of shear performance and size effect between BFRP-reinforced concrete deep beams and RC deep beams,numerical tests on static shear failure of BFRP-reinforced concrete deep beams and RC deep beams were carried out by using three-dimensional mesoscopic numerical method.Based on the existing tests,the rationality and accuracy of the simulation method were verified.The effects of beam heights,shear span-to-depth ratios and reinforcement types(BFRP bars and steel bars)on shear failure behavior and corresponding size effect of deep beams were analyzed.In addition,the simulation results were compared with those calculated based on national codes and the size effect law proposed by Jin et al.The results show that:1)The shear size effect of BFRP-reinforced concrete deep beams is more evident than that of RC deep beams,that is,as the cross-section height increases,the shear capacity and ductility of BFRP-reinforced concrete deep beams may decrease more markedly than those of RC deep beams;2)The shear span-to-depth ratio may significantly affect the shear strength of beams,but barely influence the shear size effect of beams;3)For the shear capacity of large-size beams,the safety reserve of results calculated from the codes in different countries may not be enough,and in these codes the shear span-to-depth ratio may not be considered for FRP-reinforced beams;4)The size effect law proposed by Jin et al.shall also be applicable to concrete deep beams with BFRP bars and steel bars.

关 键 词：混凝土深梁 BFRP筋 剪跨比 剪切破坏 尺寸效应 细观模拟 

分 类 号：TU375.1[建筑科学—结构工程] TU377.94