Experimental and numerical study of circular columns reinforced with steel and glass FRP bars

Fibre-reinforced polymer (FRP) bars are important replacements for reinforcements made of ordinary steel because the former offer structural durability, electromagnetic neutrality and a high strength/weight ratio, as well as being lightweight and flexible. In the present study, six concrete columns with a diameter of 29·7 cm, a height of 1·5 m but with different percentages of steel and glass FRP bars were tested for endurance under a combination of an axial load and a reversed cyclic bending load up to failure. The experimental and numerical results in terms of force–displacement hysteresis are presented and discussed in this paper. Theoretical analysis was devoted to the refined modelling of the complex hysteretic response of experimentally tested columns with ordinary and composite reinforcement. Finite-element models of the specimens were formulated using a modelling concept of refined fibre sections.