Comparative analysis of natural fiber reinforced polymer and carbon fiber reinforced polymer in strengthening of reinforced concrete beams

This paper presents a multi-objective assessment comparing the performance of natural fiber reinforced polymer (NFRP) and carbon fiber reinforced polymer (CFRP) in the flexural strengthening of RC beams. As NFRP laminates and concrete have similar elastic modulus, the NFRP-strengthened RC beams failed by FRP rupture, achieving higher ultimate loads and ductility than the CFRP-strengthened ones. Increasing NFRP reinforcement ratio and NFRP width significantly increased ultimate load and ductility. Narrow NFRP yielded higher strengthening efficiency than wide NFRP. Due to the large amount of impregnated epoxy resin, the cost advantage of natural fiber was greatly nullified and the total cost efficiency of NFRP laminates ranged between 60% and 160% that of CFRP laminates. Epoxy resin also increased the environmental impact of NFRP laminates, the NFRP and CFRP strengthening achieved similar environmental impact. Flax FRP generally yielded lower environmental impact than jute FRP. Prefabrication of NFRP laminates using vacuum infusion method is recommended to improve cost efficiency and lower environmental impact. (C) 2020 Elsevier Ltd. All rights reserved.