Steel-reinforced concrete-filled steel tubular columns under axial and lateral cyclic loading

Ebrahim Farajpourbonab,Sunil Y. Kute,Vilas M. Inamdar

doi:10.1007/s40091-018-0186-0

Abstract

SRCFT columns are formed by inserting a steel section into a concrete-filled steel tube. These types of columns are named steel-reinforced concrete-filled steel tubular (SRCFT) columns. The current study aims at investigating the various types of reinforcing steel section to improve the strength and hysteresis behavior of SRCFT columns under axial and lateral cyclic loading. To attain this objective, a numerical study has been conducted on a series of composite columns. First, FEM procedure has been verified by the use of available experimental studies. Next, eight composite columns having different types of cross sections were analyzed. For comparison purpose, the base model was a CFT column used as a benchmark specimen. Nevertheless, the other specimens were SRCFT types. The results indicate that reinforcement of a CFT column through this method leads to enhancement in load-carrying capacity, enhancement in lateral drift ratio, ductility, preventing of local buckling in steel shell, and enhancement in energy absorption capacity. Under cyclic displacement history, it was observed that the use of cross-shaped reinforcing steel section causes a higher level of energy dissipation and the moment of inertia of the reinforcing steel sections was found to be the most significant parameter affecting the hysteresis behavior of SRCFT columns.

Highlights

Composite columns have higher strength and ductility efficiency due to composite action between steel and concrete core
The results showed that composite columns had higher strength, energy absorption capacity, and ductility performance due to the composite action between steel tube, reinforcing steel section, and concrete
The reinforcing steel section has a significant role in improving the strength of steel-reinforced concrete-filled tube (SRCFT) columns and due to the lack of previous researches, this paper presents the mechanical and hysteretic behavior of different types of SRCFT columns under compressive axial and lateral cyclic loading

Summary

Introduction

Composite columns have higher strength and ductility efficiency due to composite action between steel and concrete core. These findings clearly show the considerable effects of reinforcing steel section on the behavior of SRCFT columns. Considering the curves of SRCFT and St.Steel + CFT achieved from the analysis of C 2 IPE specimen, it is obvious that at the linear section of the curves, the interaction between steel and concrete has not exhibited a higher impact on the load-carrying capacity of columns. It shows that the implementation of reinforcing steel section resulted in higher dissipated energy and a more stable hysteretic behavior for SRCFT specimens. Columns C-Cross, C 2 IPE, and CB 200 showed the best performance with regard to stiffness, the maximum shear strength, and energy absorption capacity, respectively

Summery and conclusions

Findings

Design recommendation