非蒸养UHPC-钢板结构界面的受拉和剪切性能试验研究  

EXPERIMENTAL RESEARCH ON TENSILE AND SHEAR BEHAVIOUR OF THE INTERFACE BETWEEN NON-STEAM-CURED UHPC AND STEEL PLATE STRUCTURE

作　　者：孙启力 路新瀛[1,2] 聂鑫 韩治健[1] 樊健生 

机构地区：[1]清华大学土木工程系,北京100084 [2]清华大学土木工程安全与耐久教育部重点实验室,北京100084

出　　处：《工程力学》2017年第9期167-174,192,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(51478245)

摘　　要：超高性能混凝土(UHPC)在组合结构和钢结构加固领域具有很大的应用潜力,其中UHPC-钢板界面的力学行为对整体结构组合性能的发挥起到关键作用。该文通过一系列受拉试验和推出试验,对五种常见的非蒸养UHPC-钢板界面形式进行了研究,包括光滑钢板界面、花纹钢板界面、撒入骨料的环氧胶粘剂界面、焊接弯起钢筋界面和栓钉连接界面。试验结果表明UHPC直接粘结强度较低且并不可靠;花纹钢板界面和环氧胶粘剂界面的粘结强度较高,但在受拉或无约束受剪时发生脆性破坏;焊接弯起钢筋界面和栓钉连接界面具有明显的规律性和延性,然而施加约束带来的承载力提升并不明显。该文重点研究了栓钉连接界面的力学性质,发现经典理论和现有规范严重低估了UHPC锥形破坏的承载力,提出更符合实际情况的变角度破坏面假设;此外,该文通过试验结果标定和验证了UHPC中栓钉连接件荷载-滑移关系的指数函数模型。Ultra-High Performance Concrete （UHPC） has a great potential for the application in composite construction and steel structure strengthening. The interface between UHPC and steel plate is important to the composite behaviour of the entire structure. In this paper, five kinds of interface between non-steam-cured UHPC and steel plate were investigated through a series of pure-tensile and push-out tests. The interface treatments included smooth plate; embossed plate; epoxy based adhesive with sprinkled-in aggregates, pre-bent steel rebar welding; and headed stud connecting. The results shows that UHPC has low and unreliable adhesion to the steel plate; the embossed steel-plate interface and the epoxy based adhesive interface have higher adhesion strength but brittle failure under tensile or shear loads without constraint; the pre-bent steel rebar welding and headed stud connecting treatments demonstrate evident regularity and ductility after initial interface adhesive failure, but little increase on shear capacity is observed by imposing constraint. Furthermore, the behavior of stud connection interface was specially discussed in this paper. It was found that classic theory and current codes of practice significantly underestimate the capacity of cone failure of UHPC, and an assumption of variable angle failure surface was suggested. In addition, an exponential function model for the load-slip relationship of headed studs in UHPC was calibrated and verified by the test results.

关 键 词：非蒸养UHPC 界面行为 受拉试验 推出试验 粘结强度 

分 类 号：TU398.9[建筑科学—结构工程] TU528.31