FEM on Short-Term Chloride Penetration on Carbon Fibre Reinforced Polymer (CFRP) Strengthened to RC Beam

The strengthening or repairing of reinforced concrete beams using carbon fibre-reinforced polymer (CFRP) has gained extensive attention in the field of structural engineering, realising that the CFRP has several unique mechanical properties such as high corrosion resistance, faster installation, low maintenance cost, lightweight, and high strength compared to the conventional materials. Nowadays, civil engineers are facing problems due to the corrosion of reinforced steel which leads to the deterioration of concrete. The strengthening technique was used in this research is near-surface mounted (NSM) which the CFRP reinforcement was embedded in grooves to protect them against corrosion and high temperatures. The finite element model for RC beams strengthened with NSM-CFRP was developed using LUSAS software version 19.0, a commercially available code, and specific materials behaviour models. The results obtained from FE analysis including the load–deflection relationship, maximum stress, failure mode, and crack pattern behaviour in the concrete at the mid-span section of the beam for all specimen beams have been discussed and analysed. The objectives of this study were to develop FE models of all the specimen beams, to determine the flexure performance of NSM-CFRP under chloride penetration at 28 days, and to compare the results from analytical analysis and experimental tests from previous research with the same dimensions of beams. The beams were tested and loaded in four points bending until the cracks were developed. The specimen beams were installed with CFRP and then compared with the control beam. The behaviour of these beams was simulated in a finite element model and developed in the LUSAS program. Based on the analytical analysis, found that the flexural strength of the beam strengthened with the NSM-CFRP rod has significantly increased the flexural performance by 10% compared to other strengthening materials. It has good flexural performance despite having been exposed to chloride penetration for a short-term duration. The failure modes obtained from the analyses for all the specimen beams are flexural and shear failures, and the crack pattern and maximum stress mostly occurred at the lowest bottom mid-span of the beam.