Experimental behavior and design method of rectangular concrete-filled tubular columns using Q460 high-strength steel

This paper experimentally and theoretically investigates the behavior of rectangular concrete-filled tubular (CFT) columns using Q460-grade steel. Analysis of concrete contribution ratio (CCR), ductility and strength index (SI) was performed based on the experimental results. Finite element analysis was conducted to predict the behaviors of the test columns and to choose the suitable steel material model for Q460-grade steel. A comprehensive database including this study was established to evaluate the current design approaches for rectangular CFT columns using high steel strength (HSS). Augmentation factor is proposed to evaluate the effect of both the width-to-thickness ratio and the HSS. A new design method was developed and verified to extend the steel strength limitation for designing rectangular CFT columns to 460 MPa in DB 29-57 based on this research.