Flexural strengthening of RC beams using sisal fibre reinforced polymer (SFRP) composite with anchorage systems

This research paper presents a study on the use of sisal fibre reinforced polymer (SFRP) composite as a sustainable alternative to artificial fibre reinforced polymers (FRPs) for strengthening reinforced concrete (RC) beams. Three anchorage systems, namely SE, SEM, and EE, were developed to prevent delamination of the SFRP composite from the RC beams, and their effectiveness was evaluated. The effects of SFRP composite layers, configuration, and main reinforcement ratio on the flexural capacity of RC beams were investigated. Experimental results from four-point loading tests on 15 simply supported RC beams showed that the SFRP composite improved the ductility and load-carrying capacity of the beams. Numerical analysis supported the experimental findings and successfully simulated the load-displacement curve, failure load, and failure modes of the RC beams. The research contributes to sustainable and environmentally friendly methods of strengthening RC beams and concludes that the SEM anchorage system was the most efficient in avoiding SFRP delamination, and strengthening configuration B (U-shaped) resulted in a significantly higher increase in the ultimate load-carrying capacity of RC beams due to improved bonding at the side faces of the beams. •Natural SFRP composite was examined for flexural strengthening of RC beams.•Fifteen RC beams under four-point loading were tested.•Numerous forms of anchorage systems were investigated and proposed.•Experimental results show a promising performance of the SFRP composite.•Finite element analysis of RC beams to confirm the experimental results.