Comparison between cyclic response of RC columns transversely reinforced with FRP strips and carbon steel

Abstract

This study investigates the effects of different confinement methods for longitudinal reinforcement bars in reinforced concrete, RC columns. Comparison is made between three RC columns; two were transversely reinforced with carbon steel in single tie and continuous spiral form, and the third sample were transversely reinforced with Fibre Reinforced Polymer, FRP strips in continuous spiral form. Numerical simulation is conducted using validated numerical models. All three RC column models were subjected to a constant axial load and cyclic loading. Hysteresis curves and backbone curves were used to analyse cyclic behaviour of each samples. Comparisons between the RC columns were made based on the ultimate load capacity and energy dissipation capacity ratio. Results show that, RC column transversely reinforced with FRP strips exhibits the highest ultimate load and energy dissipation capacity. The ultimate load capacity is 15% and 10% higher than the RC column transversely reinforced with carbon steel in single tie and continuous spiral form respectively. The FRP strips also increases the energy dissipation capacity up to 35% and 22% compared to the one transversely reinforced with carbon steel in single tie and spiral form respectively. It can be concluded that the usage of FRP strips as transverse reinforcement in RC column is able to improve the cyclic responses of the conventional RC columns.