Performance of sustainable fiber reinforced concrete with recycled aggregates: A critical review.

Using recycled aggregate (RA) instead of natural aggregate (NA) is one of the most sustainable choices in concrete construction in terms of decreasing the consumption of natural aggregates, reducing the landfill area, and improving the environment. However, being possesses relatively more defects compared to natural aggregates (NA), RA concrete is found to be generally associated with poor performance in terms of its mechanical performance as well as cracking behaviour. Accordingly, it is essential to implement strategies that can enhance the RA performance. For this to be tackled, a number of strategies and procedures have been proposed in numerous research works. In this regard, steel fibers, up to a certain limit, have been found to have a positive impact on RA-based concrete. The aim of the present paper is to conduct a critical review regarding the fresh and hardened properties of fiber reinforced RA-based concrete (SFRAC). The study has shown a light on the microstructure of RA and material characteristics of SFRAC. It also emphasizes the influences of steel fibers on the fresh properties, compressive strength, splitting tensile strength, and flexural strength of RA concrete mixes. The investigated properties will be discussed in terms of maximum replacement ratio, SF type and aspect ratio, and SF volume fractions (Vf). [ABSTRACT FROM AUTHOR]