The Effect of Recycled Steel Fibers from Waste Tires on Concrete Properties

One of the most severe environmental problems in the world is how to dispose of waste tires properly. Many tires are dumped or thrown away worldwide every year, severely threatening the environment. Most waste tires are used as fuel by some industries, but as we know, this type of waste use has a dangerous effect. The use of synthetic fibers, especially industrial steel fibers, which is very common today and requires high raw materials and energy, negatively impacts the environment by emitting CO2 during manufacturing. Therefore, finding fibers that perform similarly to industrial steel fibers is essential. This article presents a comprehensive overview of the methods of recycling steel fibers from waste tires, the characteristics of recycled fibers, and their application in producing different cement-based composites. The effect of these recycled fibers on fresh concrete properties, including workability and porosity, has been investigated. The effect of these fibers on the concrete's mechanical characteristics, including compressive strength, splitting tensile strength, flexural strength, impact resistance, and durability, is also discussed. According to recent research, using recycled steel fibers to strengthen concrete can be a suitable alternative to industrial steel fibers, which have fewer adverse effects on the environment and reduced recycling costs.