Use of recycled fibers in concrete composites: A systematic comprehensive review

Municipal solid waste materials are growing worldwide due to human consumption. Nowadays, a different type of goods on large-scale is produced in the factories which is going to generate numerous amount of solid waste materials in the near future. Therefore, the management of these solid waste materials is a great concern around the world. Inadequate landfill, environmental pollution and its financial burden on relevant authorities, recycling and utilization of waste materials have a significant impact compared to disposing them. Studies have been done to reuse of waste materials as one of the elements of concrete composites. Each of the elements gives the concrete strength; however, the reuse of these wastes not only makes the concrete economical and sustainable, but also helps in decreasing environmental pollution. There are a number of different types of waste materials such as plastics, carpets, steels, tires, glass, and several types of ashes. In this paper, a comprehensive review was carried out on the influence of recycled plastic fibers (RPFs), recycled carpet fibers (RCFs) and recycled steel fibers (RSFs) on the fresh, mechanical and ductility properties of concrete. The previous studies were investigated to highlight the effects of these waste product fibers on the most important concrete properties such as slump, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, ultrasonic pulse velocity, energy absorption, ductility, and toughness. In this regard, more than 200 published papers were collected, and then the methods of preparation and properties of these recycled fibers (RF) were reviewed and analyzed. Moreover, empirical models using mechanical properties were also developed. As a result, RPFs, RCFs and RSFs could be used safely in concrete composites due to it is satisfactory fresh, physical and mechanical properties. • A comprehensive review on the use of recycled fibers in concrete is presented. • RPFs, RCFs and RSFs are the commonly used recycled fibers in concrete. • The influence of different recycled fibers on the concrete properties is summarized. • A sustainable and eco-friendly as well as structurally efficient concrete can be produced by incorporating different types of recycled fibers. • Empirical models among different properties are developed.