Study On The Method For Calculation Of Flexural Strength Of Composite Column With Core Of High-Strength Concrete Filled Steel Tube

With the development of the higher-rise, large span, heavily loaded and massive scale buildings in our country, normal materials and structure types can not meet completely the demand of such a development. High-strength concrete now is wildly used due to its high strength and durability. The composite column,which consists of high-strength concrete and steel,may have advantages over either pure steel or reinforced concrete columns because the reinforced concrete can work together with inner concrete-filled steel tube harmoniously. Such new composite columns can reach the expected objective.As one of the composite columns, the high-strength concrete-filled steel tube reinforced concrete (CFSTRC), which shows a prospective application in high buildings, is endowed with better mechanical property than the common steel reinforced concrete structure, due to the confined concrete by steel tube. However, because of the little systematical research on the CFSTRC home and abroad, it is not convenient for building design, application and development.In this paper, based on the axial compression loading experiment of the CFSTRC, with the help of force equilibrium and deformation compatibility, a numerical method iwas applied in analyzing the load-deformation and behaviors of the column, the results of analysis are found to be in good agreement with those of the former test.The research shows that many factors influence the axial compression of the CFSTRC. With the numerical method built in this paper, the effects of the position coefficient, steel tube ratio, transverse reinforcement and strength of concrete on the axial compressive bearing capacity of the columns are analyzed, some beneficial conclusions are reached. On the basis of analysis and summary of current methods on the axial compressive bearing capacity of the CFSTRC, the better method of calculation is put forward.According to the lower limit principle of plastic theory and superposition method, the formulas that calculate flexural strength of the CFSTRC are derived. As a result, the universal superposition is no longer in need by repeatedly trial calculation. The influence of steel and...