Experimental study on axial compression for composite hollow column of steel fiber, high-strength lightweight aggregate concrete and angle steel

In order to study the axial compression performance for composite hollow column of steel fiber, high-strength lightweight aggregate concrete and angle steel, the axial compression tests were carried out on five composite hollow columns of steel fiber, high-strength lightweight aggregate concrete and angle steel with the variation parameters of hollow ratio (0%, 15%, 16%, 32% and 36%) and the form of opening (round hole and square hole). The failure phenomena and failure forms of the specimens were observed, and their stress-strain curves were measured, and the axial bearing capacity formula suitable for composite hollow column of steel fiber, high-strength lightweight aggregate concrete and angle steel was established. The following conclusions may be obtained from the test results: the axial compression performance for the composite hollow columns of angle steel is influenced by the hollow ratio and opening form greatly. The axial compression performance for composite hollow columns of steel fiber, high-strength lightweight aggregate concrete and angle steel is almost close to that of composite solid columns when the hollow ratio is low; The higher the void ratio, the more the cracks at the surface of the concrete, some transverse cracks appear, the peak load decreases by about 5-38%, and the deformation ductility coefficient increases gradually; The deformation ductility coefficient of round-hole hollow column is lower than that of square-hole hollow column. Based on the test, the finite element software ABAQUS is used to simulate the SCAH column. The correctness of the model is verified via the comparison between the numerical simulation results and the test results. At the same time, the stress nephogram of concrete and steel at different stages and the stress nephogram at concrete restraint state are simulated. According to the finite element simulation results, Mander model is used to calculate the axial compression bearing capacity of composite hollow column of angle steel. The high calculation accuracy and suitable for popularization can be obtained.