Parametric analysis on the flexural behaviour of RC beams strengthened with prestressed FRP laminates

In this paper, the effectiveness of reinforced concrete (RC) beams strengthened with prestressed basalt fibre -reinforced polymer (BFRP) laminates was parametrically studied through discrete displacement-coordinated finite element (FE) method. Three dimensional (3D) FE models were established based on experiments, and the reliability of the FE model was verified. The influences of material properties, prestress load level, rein-forcement ratio, and shear span on the overall behavior were investigated. The results demonstrated that the optimal capacity of strengthened beam can be achieved in large shear span with low reinforcement ratio and high-strength concrete. The cracking load of RC beams was also significantly increased by strengthening with prestressed BFRP laminates. Then, polynomial equations were fitted to quantify the influences of different pa-rameters on capacity enhancement. The shear span ratio was found to be the most important factor. In addition, the utilisation efficiency of BFRP is much higher than that of carbon FRP (CFRP) with the same section and prestress level due to the strong deformation ability.