Experimental Study On Fire Resistance Of Shaped Steel Reactive Powder Concrete Biased Columns

Reactive powder concrete(RPC)columns are mainly composed of steel encased with reactive powder concrete(RPC)and a certain amount of reinforcement.RPC is widely used in bridge engineering and ocean engineering due to its strong permeability resistance,good wear resistance and ultra-high strength.Steel reinforced concrete members have been widely used in recent years due to their high bearing capacity and superior seismic performance.Therefore,with the frequent occurrence of building fires,how to ensure the fire safety of the structure,and understand the fire resistance performance and fire resistance mechanism of Steel Reinforced Reactive Powder Concrete Members under high temperature are always the problems we need to study.In this thesis,combined with the domestic and foreign research on the high temperature performance of reactive powder concrete materials and the performance of steel reinforced concrete(including RPC)structure under high temperature,five steel reinforced reactive powder concrete columns are designed and poured,and the dead load test under high temperature is carried out.The influence of different eccentricity and eccentric direction is mainly considered.The test data and phenomena are analyzed and simulated by finite element method The results are as follows:1)Through the observation of the failure phenomenon of five specimens,the characteristics of specimens under high temperature are obtained,and the different failure characteristics and crack distribution laws of axial compression specimens and eccentric compression specimens under different eccentricity and eccentric direction are compared and summarized.2)Through the arrangement and analysis of the temperature measuring points of the specimen,the temperature rising law and variation characteristics of the specimen section at high temperature are summarized.3)By sorting and analyzing the time temperature curves of specimens,the failure characteristics of different specimens are summarized.The displacement of unidirectional eccentric specimens increases almost linearly,showing obvious brittle failure characteristics,while the displacement of bidirectional eccentric specimens increases more gently,showing a certain ductile failure characteristics.4)Through sorting and analyzing the fire resistance time of the specimen,the fire resistance time decreases with the increase of eccentricity.Compared with the axial compression specimen and the unidirectional eccentric specimen,the fire resistance time of the biaxial eccentric specimen is shorter when the axial compression ratio and eccentricity are fixed.5)The finite element analysis software ABAQUS is used to analyze the whole process of the test.In the temperature field simulation,it is found that the numerical analysis results are in good agreement with the experimental research.The thermal mechanical coupling analysis is introduced to verify the experimental research,and the error is within a reasonable range.On the basis of the experimental research,the variation range of influencing factors is expanded,and the law obtained from the experimental research is verified.