Reinforcing circular concrete columns reinforced with GFRP bars and helices

H. Karim, M.N. Sheikh, M.N.S. Hadi
University of Wollongong,
Australia

Keywords: GFRP bar, GFRF helix, Reinforced concrete, Column

Summary:

In order to achieve long-term durability for Reinforced Concrete (RC) structures, Glass Fiber Reinforced Polymer (GFRP) bars are used as alternatives to traditional steel reinforcement in RC structures. Although RC building and bridge columns in coastal areas are susceptible to significant deterioration, studies on concrete columns reinforced with GFRP bars and helices are limited. Moreover, design codes do not recommend the use of GFRP bars in compression members. This study investigates the use of GFRP bars and helices as longitudinal and lateral reinforcement, respectively, in concrete columns. Five circular normal strength RC columns with 205 mm in diameter and 800 mm in height were cast and tested under concentric loads. The influence of the longitudinal GFRP reinforcement and the spacing of the GFRP helices on the strength and ductility capacity of the columns were investigated. The experimental results showed that the contribution of the longitudinal GFRP bars was lower than the contribution of longitudinal steel bars to the load carrying capacity of the columns. Also, the load carrying capacity of the GFRP-RC columns was smaller than that of steel-RC columns. However, the ductility capacity of the columns was not affected by the use of GFRP helix instead of steel helix.