The recent progress of recycled steel fiber reinforced concrete

Environmental issues such as exhaustion of natural resources and generation of enormous amounts of waste and their dumping are currently steering the modern civilization to sustainable construction. Steel fiber reinforced concrete has been in application for many decades because of its capability in arresting crack and introducing ductility to structural concrete. Concerning about natural resources and adverse environmental impact of CO₂ emission during the production of industrial steel fibers at a larger scale, significant research efforts have been made towards sustainable, resource conservative and recycled alternatives to replace these high-cost commercially available steel fibers with recycled steel fibers (RSFs). Recycled steel fiber reinforced cement mixtures behaves differently in fresh and hardened states compared to plain and industrial steel fiber reinforced cement mixtures. This review provides a brief overview of the recycled steel fibers from different sources, their characteristics, and application in the production of various cement-based composites. Effect of RSFs on the different properties of concrete in fresh state including workability, porosity, bulk density, and volumetric stability has been addressed. Detail discussion on the mechanical properties of various cementitious systems has been included, comprising compressive and flexural strength, tensile splitting strength, toughness, resistance to impacts and durability of RSFRC. This study aims to critically examine the currently reported literature and to identify research gaps for those who intend to further study of behavior of recycled steel fiber reinforced cementitious systems for various applications.