Experiments and analytical model for axial strength of FRP-reinforced reactive powder concrete circular columns under axial compression

Although various experimental studies have been performed in the literature to explore the behavior of glass fiber reinforced polymer (glass-FRP) reinforced conventional concrete columns, no study focused on the axial performance of glass-FRP-reinforced reactive powder concrete (RPC) columns (GRPC columns) subjected to compression. Therefore, the current struggle investigates the behavior of nine GRPC columns through experimental testing, finite element analysis (FEA), and theoretical models on the circular samples with 250 mm diameter and 1000 mm length under axial compression. Steel fibers are added to RPC to minimize brittleness and to improve the strength of RPC. Moreover, a parametric study is planned to utilize the suggested FEA model for exploring the effects of various variables of GRPC columns on axial structural performance. The test findings showed that the GRPC columns become more ductile with the addition of fibers and a reduction in the vertical distance between the glass-FRP hoops/ties. The failure of GRPC columns occurred in the middle region of the samples with the delayed spalling of the concrete cover. The suggested analytical model based on the 600 data points presented higher accuracy than previous theoretical models. The recommended FEM for the axial capacity and associated axial shortening of examined samples portrayed errors of 3.25% and 4.65%, respectively. Considering the axial contribution of glass-FRP longitudinal bars and the transverse confining mechanism of FRP stirrups, the recommended theoretical model for the axial capacity of GRPC column samples performed well for the test findings of the examined samples with R² = 0.842, MSE = 139.559, MAE = 195.538, and RMSE = 200.756.