Post-earthquake Fire Behavior Of Post-installed Connections Between Steel And Concrete

The post-installed anchorage is widely used in the field of structural retrofit and strengthening.But the existing investigation concentrates on the performance of post-installed anchorage under the action of seismic and high temperature respectively while the coupling effect of earthquake and post-earthquake fire is seldom considered.In this paper,the post-installed connections between steel and concrete is investigated with the methods of numerical simulation and experimental research.Firstly,the damage model of post-installed connection joints is put forward under seismic effect,and the seismic damage assessment of residual strength is presented.And then further study on high temperature behavior of damaged connection joints is carried out,and the aim of this study is to reveal the temperature distribution of each part of the structure under fire.The main research achievements are shown as follows:(1)The applicability of the existing damage model is checked according to the existing test data.And then the damage model of post-installed connection between steel and concrete is put forward as well as the damage classification of members under earthquake and the corresponding damage index range is given,which provides suggestions for the seismic damage assessment of the post-installed connection joint.(2)Experimental researches of post-installed connection joint with different kind of cyclic loads are presented and the behavior of load bearing,displacement and the damage state are explored.(3)The finite element software-ABAQUS is used to simulate the behavior of post-installed connection joint under cyclic load.The result is satisfied well with data and phenomena of experiment in test.Then the method of seismic damage assessment of residual loading bearing capacity of this kind of connection joints is presented.(4)High temperature test of the post-installed connection joints with seismic damage is carried out,and the temperature field of steel member and reinforcements are analyzed.Then the monotonic loading test of the post-installed connection joints after exposure to fire is completed and test result indicates that the behavior of loading bearing as well as rigidity shows different degrees of decline,which compared with result of simulation ofcyclic load tests and high temperature tests shows that the components suffer greater damage under seismic and high temperature coupling effect.(5)The finite element software-ABAQUS is used to simulate the behavior of post-installed connection joints under high temperature.The simulation result shows that when post-installed connection joints exposed to high temperature,external heat transfers from the end of anchors to internal part by the steel beam and anchor plate,meanwhile it also transfers by heat conduction along the concrete surface to the inner anchor adhesive.Therefore,different modes of heat transfer and path cause the temperature gradient along the length direction.