Analytical Investigation of Concrete Beam Reinforced with GFRP Rebars Under Low Axial Loading

Abstract

The main objective of the research presented in this paper was to perform the analytical study to investigate the flexural capacity of the concrete beam reinforced longitudinally and laterally with glass fiber-reinforced polymers (GFRP) bars subjected to low axial compressive load. If the GFRP beam is subjected to compression due to any accidental wind or seismic load, ignoring compression during this condition might not be conservative. To characterize the flexural capacity of the beam under low axial loading – the study was performed considering the specimen with a cross-sectional size of 300 x 400 mm with a concrete grade of 40 MPa and reinforcement ratio of 4%. The analytical model was developed using PTC MATHCAD Prime to carry out the analysis for the sand coated GFRP reinforced concrete beam. From the analytical study results of a beam, the interaction diagram showed that the ultimate bending resistance of the beam decreases with the application of lower load in the range of 5 to 10 % of its axial capacity. Further with the analytical model, a parametric study was performed to investigate the effect of reinforcement ratio, concrete strength, and axial load. As part of this ongoing research, an experimental investigation is further carried out at Dalhousie University to verify the analytical study by testing the full scale GFRP concrete beam under Four-point bending with low axial compressive loads applied at both ends of the beam. During the time of the conference presentation, there will be more test data available to endorse the analytical behavior of the GFRP reinforced concrete beam presented in this paper.