Mechanical properties of steel reinforced reactive powder concrete columns under axial compression

With the continuous development of building structures and the increasing demand for use, the composite structure of steel reinforced reactive powder concrete (SRRPC) with excellent bearing capacity, stiffness, ductility, fire resistance and seismic performance was proposed. In this paper, the SRRPC column model was established by finite element software ABAQUS to investigate mechanical characteristics, and consistency within the model and the test results were verified from the aspects of failure phenomenon, load-displacement curve and bearing capacity. On this basis, the influence of calculated length, section steel strength, reinforcing bar strength, stirrup ratio and concrete strength on the mechanical characteristics of SRRPC columns was investigated. The consequences show that: (1) The bearing capacity rose with the rise of concrete strength, section steel strength, reinforcing bar strength and stirrup ratio, and decreased with the rise of calculated length. (2) On the basis of sensitivity analysis of parameters, bearing capacity is highly sensitive to concrete strength and section steel strength, generally to stirrup ratio and calculated length, and minimally to reinforcing bar strength. (3) The load entering the elastic-plastic stage increased with the rise of concrete strength, section steel strength and stirrup ratio, and decreased with the increase of calculated length. (4) The stiffness increased in each phase with the rise of concrete strength, section steel strength, reinforcing bar strength and stirrup ratio, and changed the most in phase C (0.5-0.75 P-u). The stiffness in each phase decreased with the increase of the calculated length, and changed the most in phase B (0.25 similar to 0.5 P-u). Finally, the calculation method of bearing capacity was proposed.