考虑骨料粒径影响的BFRP筋混凝土梁剪切破坏及尺寸效应  

Shear failure and size effect of BFRP reinforced concrete beams considering aggregate size

作　　者：金浏[1] 陆凯 宋博[1] 蒋轩昂 杜修力[1] JIN Liu;LU Kai;SONG Bo;JIANG Xuan;ang;DU Xiuli(The Key Laboratory of Urban Security and Disaster Engineering,Beijing University of Technology,Beijing 100124,P.R.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：《土木与环境工程学报（中英文）》2023年第3期34-43,共10页Journal of Civil and Environmental Engineering

基　　金：国家重点研发计划(2018YFC1504302);国家自然科学基金(51822801、51421005)。

摘　　要：粗骨料是混凝土材料的组成之一,其粒径变化会影响混凝土梁中骨料咬合作用对抗剪承载力的贡献。为了系统地考虑最大粗骨料粒径对玄武岩纤维增强聚合物(Basalt Fiber Reinforced Polymer,BFRP)筋无腹筋混凝土梁剪切破坏的影响,采用细观尺度数值模拟方法,建立BFRP筋无腹筋混凝土梁数值模型,模拟分析构件尺寸和粗骨料粒径对BFRP筋混凝土梁剪切破坏模式和抗剪强度的影响规律。结果表明:BFRP筋无腹筋混凝土梁的抗剪强度存在尺寸效应,同时,随着最大粗骨料粒径的增大,BFRP筋混凝土梁的抗剪承载力提高,梁的剪切尺寸效应被削弱。根据最大粗骨料粒径的影响机制与规律,结合断裂力学尺寸效应律,建立了BFRP筋混凝土梁抗剪强度尺寸效应理论公式,并与模拟结果和试验数据进行对比,验证了公式的准确性和合理性。Coarse aggregate is an important proportion of concrete material,and the change of its size will affect the contribution of aggregate interlock behaviour in concrete beams to shear capacity.In order to consider the effect of the coarse aggregate size on the shear failure of Basalt Fiber Reinforced Polymer(BFRP)beams without stirrup systematically,the meso-scale simulation was selected and a numerical model of BFRP reinforced concrete beams without stirrup was established.The effects of member size and coarse aggregate size on the shear failure mode and shear strength of BFRP reinforced concrete beams were simulated and analyzed.The results show that the size effect exists in the shear strength of BFRP reinforced concrete beams without stirrup.Meanwhile,the increase of the maximum aggregate size improves the shear capacity of concrete beam,and weakens the size effect of shear strength.According to the influence mechanism and law of maximum coarse aggregate size,theoretical formula of size effect on the shear strength of BFRP reinforced concrete beams was established on the basis of Fracture-SEL,and its accuracy and rationality are verified via experimental data.

关 键 词：BFRP筋 混凝土梁 粗骨料粒径 抗剪强度 尺寸效应 细观模拟 

分 类 号：TU377.9[建筑科学—结构工程]