Behaviour of hollow and solid concrete-filled circular steel tubular simple beams

Abstract

This paper deals with the results of analytic, experimental and numerical investigation of the hollow and solid concrete-filled steel tubular simple beams. Overall interaction between the external thin-walled circular steel shell and the internal concrete core significantly increases the bending resistance, ductility and durability of such beams in comparison with the steel or concrete flexurai members. The circular steel tubes have been chosen for investigation taking into account the simplicity of manufacture of concrete-filled CHS by simple casting, or especially for forming the hollow concrete cores by centrifugmg. The great torsional capacity of tubular members as well as great local buckling capacity of wall of CHS of concrete-filled members were taken into account too. For calculation of the bending resistance of such members two methods have been applied: one recommended by EC4, and, second, method of design based on the test data. Furthermore, obtained design results were compared to determine their interrelationship and with the results of carried out natural and numerical testing. Results of carried out investigation have proved sufficiently great durability and reserve of bending resistance of hollow and solid concrete-filled steel tubular simple beams. There is presented giving better agreement developed method for design oi hollow and solid concrete-filled circular steel tubular simple beams based on test data what allows recommending the developed method to use in design practice.