植筋UHPC-NC界面直剪试验研究及有限元模拟  

Straight Shear Test and Finite Element Simulation of UHPC-NC Interface with Reinforcement Planting

作　　者：鲜雪蕾 林梦凯[1] 陈天明 王大宁 XIAN Xuelei;LIN Mengkai;CHEN Tianming;WANG Daning(Department of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《硅酸盐通报》2024年第6期2056-2063,2072,共9页Bulletin of the Chinese Ceramic Society

基　　金：甘肃省自然科学基金(22JR5RA334);甘肃省高等学校创新能力提升项目(2019B-055)。

摘　　要：目前,超高性能混凝土(UHPC)被广泛用于组合构件和普通混凝土(NC)结构的加固。在加固后,由于界面法向拉应力和界面切向剪应力的共同作用,UHPC与NC之间的界面成为最脆弱的部分。植筋处理是连接旧混凝土与新混凝土界面的常见方法。本研究通过直剪试验和有限元模拟综合分析了有无植筋的UHPC-NC试件的抗剪强度以及植筋率对抗剪性能的影响。结果表明,无植筋试件的抗剪强度仅为整体浇筑试件的20%,而植筋试件的抗剪强度为整体浇筑试件的40%~80%。在未植筋试件中,破坏形式呈脆性破坏,而在植筋试件中,界面裂缝得到发展,界面抗剪强度提高,界面滑移量增大,界面呈延性破坏。At present,ultra-high performance concrete(UHPC)is widely used for reinforcement of composite members and normal concrete(NC)structures.After reinforcement,the interface between UHPC and NC becomes the most vulnerable part due to the combined effect of interface normal tensile stress and interface tangential shear stress.Reinforcement planting treatment is a common method to connect the interface between old concrete and new concrete.In this study,the shear strength of UHPC-NC specimens with and without reinforcement planting and the effect of reinforcement rate on shear performance were comprehensively analyzed by straight shear test and finite element simulation.The results show that the shear strength of specimens without reinforcement planting is only 20%of that of integrally cast specimens,while the shear strength of the reinforcement planting specimens could reach 40%to 80%.In specimens without reinforcement planting,the damage form is brittle damage.In reinforcement planting specimens,the development of interface cracks is controlled,the interface shear strength is improved,the slip of interface slip is increased,and the interface is ductile failure.

关 键 词：UHPC 新老混凝土 植筋加固 粘结面 剪切性能 植筋率 

分 类 号：TU753.8[建筑科学—建筑技术科学]