Using Recycled FRP Composites to Develop Sustainable Concrete: A State-of-the-Art Review Article

The use of fiber-reinforced polymers (FRPs) has quickly grown during the past decades due to their strength, durability, and versatility. Although, given the first use of FRPs, in the 1980s, and their service life of 20 to 40 years for wind turbine blades and 50 to 70 years for FRP bars in structures and bridges, it is anticipated that a huge amount of FRP waste will accumulate in the upcoming years. Given this fact and the non-renewability of FRPs, reusing them could be considered the most promising approach. Many researchers studied using recycled FRP composites as aggregate, filler, and fibers to reduce the demand for aggregate and/or cement in concrete materials, slowing down resource depletion. Unfortunately, the application of recycled composites in concrete and their impacts on the compressive strength of concrete properties have not been comprehensively determined. However, the existence of a review article on using recycled FRP composites can identify the gaps and provide valuable insight for future studies. Therefore, this article aims to comprehensively examine the influence of using recycled FRP composites in concrete based on recent literature. Results demonstrated that the main adverse impact of using recycled FRP bars and blades is due to the low strength of their interfacial transition zone with cement paste in the cementitious composites. Nonetheless, findings demonstrated that the impact of using recycled FRP composites is similar to that of concrete-recycled aggregates, showing their potential as an alternative for recycled aggregates.