Axial performance of GFRP-reinforced fibrous self-consolidating concrete columns

To date, fiber-reinforced concrete columns reinforced with fiber-reinforced polymer (FRP) bars under concentric axial load have generated only a small amount of attention. Incorporating fibers in FRP-reinforced concrete columns can increase the ductility in terms of post-cracking and deformation. This study analyzed the axial compressive behavior of fibrous self-consolidating concrete (SCC) columns reinforced with glass-FRP (GFRP) longitudinal and transverse bars. In order to fulfill the objectives of this research, 10 full-scale fibrous SCC columns were tested: one had no reinforcement and served as a reference, one had steel reinforcement, and the remaining eight were designed to determine the outcomes of increasing the GFRP longitudinal bar ratio (1.65%, 2.20%, and 3.30%), enhancing the GFRP spiral pitch (40, 60, 80, and 120 mm), and various transverse GFRP reinforcement configurations (spiral and hoop). According to the test findings, adding fibers improved the ductility and post-peak behavior of the columns reinforced with GFRP bars. Furthermore, increasing the GFRP longitudinal reinforcement ratio from 1.65% to 3.30% resulted in an insignificant 4% increase in the first peak load. Decreasing the GFRP spiral pitch from 120 mm to 40 mm increased the columns’ first peak load, second peak load, and ductility index by approximately 8%, 47%, and 78%, respectively. Lastly, the data obtained through this research was used to conduct an analytical study to determine the load-carrying capacity and confinement of the fibrous SCC columns reinforced with GFRP bars and spirals. • Fibers enhanced ductility and delayed concrete spalling in GFRP-reinforced SCC columns. • Spiral pitch reduction from 120 mm to 40 mm greatly improved strength and ductility. • GFRP hoops with 200 mm lap provided confinement equal to that of spiral reinforcement. • Increasing GFRP bar ratio changed failure mode but had little effect on peak load. • Experimental results were used to evaluate and validate existing confinement models.