A comprehensive review on the use of natural fibers in cement/geopolymer concrete: A step towards sustainability

The construction industry is shifting towards environmentally friendly products due to the rising demand for non-renewable raw materials, their high energy consumption, and, most importantly, their detrimental environmental effects. High levels of solid waste produced by raw materials release dangerous gases like nitrous and Sulphur oxides, which are very harmful to the environment. In recent years, the usage of fibers has tremendously increased to make significantly robust structures. For sustainable, waste-free development, manufactured fibers can be replaced with natural fibers without compromising on the requirements. This study considers various natural fibers like basalt, coconut/coir, banana, sugarcane bagasse, hemp, kenaf, bamboo, jute, sisal, abaca, and cotton, and their effects on fresh and hardened concrete have been discussed. This article also reviews the composition, preparation, and processing procedures of various natural fibers, and their potential applications in building materials are highlighted. Future research avenues are identified, and possible negative impacts and limitations are discussed. Our findings confirm the feasibility of standard concrete using natural fibers in cement or geopolymer concrete. Lastly, this review compiles insights from numerous sources to aid academia and the construction industry in developing eco-friendly materials.