Experimental and Numerical Study of Carbon Fibre-Reinforced Polymer-Strengthened Reinforced Concrete Beams under Static and Impact Loads

Abstract

This study aims to investigate the behaviour of reinforced concrete (RC) beams strengthened by Carbon Fibre-Reinforced Polymer (CFRP) under static and impact loads. A series of RC beams were tested and categorized into four groups, namely, unstrengthened RC beams (B1), RC beams strengthened with a CFRP longitudinal strip in the tension zone (B2), RC beams wrapped with CFRP fabric (B3), and RC beams strengthened with a combination of both CFRP longitudinal strips and wraps (B4). The results show that the average load–displacement capacity of RC beam group (B4) was improved by 84.88% as compared with the unstrengthened beam (B1) under static loads. The dynamic test results demonstrated an increase in the deflection resistance of RC beam group (B4) by −57.89% as compared with unstrengthened RC beam group (B1) under identical drop weights of 1 m. In addition, a collapse failure mode was noticed in the unstrengthened beams, while minor damage was recorded mainly in the case of RC beam group (B4). Furthermore, the numerical analysis conducted using LS-DYNA software (V 971 R6.0.0) proved that the adopted numerical models can efficiently predict the behaviour of RC beams under dynamic loads, with maximum differences reaching up to −12.5% compared with the experimental test results.