Experimental Study On Mechanical Properties Of Axial Loaded High Strength Steel Reinforced Concrete Composite Column

With the rapid development of super high-rise and super long-span structures,steel-reinforced concrete composite structures have been widely used in building structures due to their high bearing capacity and excellent seismic performance.At the same time,with the development of metallurgical technology and the deepening of the concept of green building,the Chinese government vigorously promotes the application of high-strength steel in the field of building structures.The application of high-strength steel in the composite structure of steel-reinforced concrete can make the two materials complement each other.However,studies have shown that the compressive performance of high-strength steel is restricted due to the influence of concrete compressive strain.At present,the related research on the application of high-strength steel to composite structures needs to be supplemented and perfected,and in Chinese design codes,the design regulations for the application of Q420 or higher steel to composite structures are not yet clear,which affects the popularization and application of high-strength steel-concrete composite structures.Therefore,it is necessary to conduct a special study on it to investigate the influence of different factors on the axial compressive performance of high-strength steel-reinforced concrete columns.The main work content is as follows:(1)Design and manufacture high-strength steel-concrete column specimens with Q460 and Q690 steels and comparative specimens with Q235 steels based on the test parameters of section steel strength grade,steel content,slenderness ratio,and stirrup ratio.Carry out the axial static load test.(2)Analyze the bearing capacity and failure phenomenon of specimens,organize the data to draw the load-displacement curves and load-strain curves,and analyze the influence of each parameter on the bearing capacity and failure process of specimens.Experimental research shows that the use of high-strength section steel can significantly increase the axial compressive bearing capacity of the specimen.When certain stirrup ratio conditions are met,both Q460 and Q690 high-strength section steels can give full play to the compressive performance of the material.(3)In order to further study the mechanical performance and failure mechanism of high-strength steel-concrete columns under axial load,the ABAQUS finite element simulation software was used to establish the analysis model of the specimens,and the simulation results were compared with the test results,and the effect of restraint action of concrete on the bearing capacity of the specimens was discussed.(4)Calculate the bearing capacity of the specimens according to the relevant regulations of China,the United States,and the European composite structure design code,then compared with the test results to investigate the applicability of each code when applied to Q460 and Q690 high-strength steel,and based on the restraint effect,the design suggestions of axial compression bearing capacity of high-strength steel-reinforced concrete columns are put forward.