The Contribution of Tire Recycled Materials in the Circular Economy of Cement-Based Composites

This chapter delves into the innovative use of tire recycled materials (TRM) in cement-based composites, focusing on the substitution of natural aggregates with rubber granulates and the reinforcement of concrete mixtures with recycled steel fibers. The study investigates the mechanical properties and environmental impacts of three different mortar mixtures: a standard mortar, a mortar with rubber granulates, and a mortar with both rubber granulates and recycled steel fibers. The findings reveal that while the addition of rubber granulates reduces the flexural strength of the mortar, the inclusion of recycled steel fibers can enhance both the mechanical performance and the environmental sustainability of the composite. The chapter also explores the limitations of current green public procurement (GPP) prescriptions, which mandate the use of at least 5% recycled materials in public constructions. Through life cycle assessment (LCA), the study demonstrates that the environmental impact of rubber concrete can sometimes be higher than that of traditional concrete, despite the use of recycled materials. The chapter concludes by emphasizing the importance of a comprehensive, life cycle perspective in evaluating the environmental impact of building components and materials. It also highlights the potential of properly using TRMs to reduce the global warming potential (GWP) of structural elements, despite the slight increase in CO2 emissions at the material level.