Experimental study on eccentric compression behavior of slender rectangular concrete columns reinforced with steel and BFRP bars: Fid-Bau Portal

Experimental study on eccentric compression behavior of slender rectangular concrete columns reinforced with steel and BFRP bars

Liu, Shui / Wang, Xin / Ali, Yahia M.S. / Huang, Huang / Zhou, Jingyang / Wu, Zhishen

Abstract

Highlights • The eccentric compression behavior of concrete columns reinforced with a combination of steel and BFRP bars was experimentally studied. • The effects of loading eccentricity, reinforcement type, and reinforcement ratio were discussed. • The equations to predict the axial compressive strength of hybrid-RC columns were proposed.

Abstract This study aims to investigate the eccentric compression behavior of concrete columns reinforced with a hybrid of steel and basalt fiber-reinforced polymer (BFRP) bars and ties (hybrid-RC). A total of ten slender columns were constructed and tested, including six hybrid-RC columns, two longitudinal steel bars and ties reinforced concrete (steel-RC) columns, and two longitudinal BFRP bars and ties reinforced concrete (BFRP-RC) columns. The study focused on the effects of reinforcement type, loading eccentricity, and reinforcement ratio. The test results indicated that the hybrid-RC columns with relatively higher reinforcement ratios demonstrated close load-carrying capacity and stiffness to those of steel- and BFRP-RC columns. All the columns experienced a significant reduction in their load-carrying capacities, as well as the axial and lateral stiffness, when the applied loading eccentricity increased from 80 mm to 150 mm. As the reinforcement ratio increased, hybrid-RC columns exhibited an improvement in the load-carrying capacity, stiffness, and axial force contribution of longitudinal bars in compression. Furthermore, the equations to predict the cross-sectional strength of hybrid-RC columns were proposed by theoretical analysis, and the existing methods considering the slenderness effect were evaluated for hybrid-RC columns.