Experimental and Numerical Investigations on the Composite Behavior of Concrete-Filled Tubular Columns with Massive Steel Core at High Temperatures

Abstract

This paper deals with experimental and numerical investigations on concrete-filled tubular columns with embedded massive steel core (CFTES columns) aiming at justified design recommendations on reliable shear stresses.. Push-out tests at room temperature and high temperatures are described in detail and analyzed in terms of ultimate shear strength, bond strength and shear strength-displacement-curve shape. The test data reveal a distinctive reduction in both ultimate shear and bond strength for high temperatures, whereas the strength-displacement-curve shape is in general similar for all investigated temperature levels. The numerical implementation of the performed tests reproduces the experimentally observed shear strength-displacement-behavior in very good accordance. Using a three-dimensional volume model in Abaqus and applying temperature-dependent joint stiffness, maximum shear stress criterion and damage evolution, the composite behavior is described in a realistic manner.