Experimental And Finite Element Study On Fire Resistance Of Stainless Steel Reinforced Concrete Columns

Concrete filled stainless steel tube(CFSST)refers to the stainless steel tube filled with concrete components,stainless steel tube and the concrete stress at the same time.On this basis,the shaped steel is arranged in the stainless steel pipe concrete to form a stainless steel pipe concrete.Its superior performance depends on the cooperation of stainless steel pipes and concrete and built-in steel,but the interaction mechanism between the three materials is more complicated.Under the effect of high temperature,the temperature of the outer stainless steel tube is very high,and the core concrete has a non-uniform temperature field,that is,the temperature of the outer concrete is significantly higher than the inner concrete temperature,so that the strength loss of the built-in steel is small,and the effective section bearing capacity of the test piece is improved.At the same time,the presence of built-in steel can reduce the thickness of the outer stainless steel tube and reduce the engineering cost.At present,a number of studies have been conducted on the fire resistance of stainless steel pipe concrete under fire conditions at home and abroad.However,there has been no report on the research on the fire resistance of rigid stainless steel tube concrete.Based on the above background,the fire resistance of rigid stainless steel tube concrete is tested in this paper.The main work and results are as follows:(1)The fire-resistance limit test of six specimens of stainless steel concrete columns was performed.The temperature-time curves,load-displacement curves and fire resistance of the specimens were obtained.The effects of the factors such as the cross-section dimensions,load ratio,and size of the steel on the fire resistance of thespecimen were analyzed.(2)The finite element model of the rigid stainless steel concrete column was established,and the temperature field and force field were calculated.The relevant tests were used to verify the validity and applicability of the finite element model.(3)The parameter analysis of the fire resistance of the stainless steel concrete column was carried out.The results showed that the fire resistance of the rigid stainless steel tube concrete increases with the increase of the section size of the specimen,and decreases significantly with the increase of the load ratio.The fire resistance of the test piece can be significantly increased;the strength of the concrete,the type of the steel and so on have little effect on the fire resistance of the test piece.