Study On Fire Resistance Of Grout Sleeve Splicing Of Rebars

In the prefabricated buildings,the grout sleeve splicing of rebars is usually used as the connection mode between the prefabricated parts,so that different prefabricated parts are connected together to form a whole and jointly resist various adverse loads from the outside.It can be seen that the grout sleeve splicing of rebars is of great importance to the prefabricated building.With the funds support of Natural Science Foundation of Liaoning province(Grant:2015020600).This paper mainly includes the following contents:Using the finite element software ABAQUS and based on the relevant experimental data the connect ?16,?20 and ?25 reinforced grout sleeve splicing of rebars(labeled D16,D20 and D25)numerical analysis model is established,and thermodynamic coupling analysis was carried out for the three analysis models,and the simulation results were compared with the experimental data to verify the feasibility of the model.Base on the basis of the finite element model of the grout sleeve splicing of rebars,the effects of different temperature and fire time on the mechanical properties of the three components were analyzed,the stress distribution of steel bar,sleeve and grouting material is analyzed when three kinds of components are subjected to the limit drawing load at high temperature.At the same time,the displacement-load curves of the three components are analyzed,and the effects of different temperature and fire time on the ultimate bearing capacity of the three components are analyzed.The research results show that:Under the two high temperature conditions of different temperature and different fire time,when the three members are subjected to the ultimate bearing capacity,the Mises stress of the steel bar gradually decreases from the bearing end to the non-bearing end of the steel bar,and the stress rib of the steel bar at the bearing end of the steel bar occurs.The value of the Mises stress of the sleeve increases first and then decreases from the top end to the bottom end of the sleeve.The Mises stress distribution of the grout is uniform and the range of numerical variation is small.The ultimate bearing capacity of the three members decreases with increasing temperature,and the reduction is small before 400?.Above 400?,the ultimate bearing capacity of the member drops sharply;the ultimate bearing capacity of the three members also decreased to varying degrees with the increase of the fire time,before 10 minutes,the ultimate bearing capacity of the three members decreased slowly,especially the D25 components showed almost no decline,Between 10 minutes and 20 minutes,the ultimate bearing capacity of the three components drops sharply,after 30 minutes,almost all of the three components lost their load carrying capacity.