Mechanical behavior of high-strength RPC filled circular and square steel tube considering size effect and interface bond

Abstract

With consideration of interface bonding performance and size effect, the unified solutions of bearing capacity for reactive powder concrete (RPC) filled circular and square steel tube are presented based on the unified strength theory (UST) and thick-walled cylinder theory. Parametric studies are carried out to investigate the influence of the unified strength theory parameter, confinement index and RPC strength. It is shown that proper choices of influential parameters are significant in the design of such components. The calculation formulas with regard for interface bond and size effect match better with the experimental data. Through the statistical analysis, the theoretical formula and the calculation method in the technical regulation is verified. Compared to the technical specifications, the proposed calculation formulas are more precise. It is concluded that the practical calculation formulas have an important practical value for the optimum design and engineering application of RPC filled steel tube.