新型装配式高强钢筋混凝土框架节点受力性能

Mechanical behavior of new type prefabricated high strength reinforced concrete frame joints

对2个装配式高强钢筋混凝土框架节点试件与1个现浇高强钢筋混凝土框架节点试件进行低周往复荷载试验.对比分析节点试件的破坏形态、延性及承载力等抗震性能指标和钢筋应变、连接杆应变等受力性能指标.试验结果表明:各试件节点均为核心区剪切破坏,钢纤维的加入可以有效减小核心区裂缝宽度,有效改善节点核心区破坏形态;装配式节点承载力比现浇节点有显著提高,但装配式节点的延性比现浇节点稍差;装配式节点的核心区箍筋达到屈服强度,连接杆能够充分发挥作用,装配式混凝土节点的受力性能优于整体现浇混凝土节点.运用ABAQUS对各节点试件进行有限元模拟,分析轴压比、钢筋钢板强度等级等因素对装配式高强钢筋混凝土节点受力性能的影响.钢板强度等级对节点受力性能影响较大.有限元分析结果与试验结果吻合良好,建立的模型能够用于模拟装配式混凝土节点的抗震性能.

The low cyclic loading tests were carried out on two specimens of prefabricated high-strength reinforced concrete frame joints and one cast-in-place high-strength reinforced concrete frame joint.The seismic performance indexes,such as failure mode,ductility and bearing capacity,and the mechanical performance indexes,such as reinforcement strain and connecting rod strain,were compared and analyzed.The test results show that the failure mode of all joints is shear failure in the core area and the addition of steel fiber can effectively reduce the crack width in the core area and effectively improve the failure mode in the core area of the joint.The bearing capacity of the assembled joint is significantly higher than that of the cast-in-place joint,but the ductility of the assembled joint is slightly worse than that of the cast-in-place joint.The stirrup in the core area of the prefabricated concrete joint can reach the yield strength,and the connecting rod can play a full role.The mechanical performance of the prefabricated concrete joint is better than that of the integral cast-in-place concrete joint.ABAQUS was used to carry out finite element simulation on each joint specimen to analyze the influence of factors such as axial compression ratio and steel plate strength grade on the mechanical performance of prefabricated high-strength reinforced concrete joints.The strength grade of steel plate has great influence on the mechanical properties of joints.The finite element results are in good agreement with the experimental results,and the established model can be used to simulate the seismic behavior of prefabricated concrete joints.