Enhancing Concrete Pavement Durability with Recycled Steel Fiber Extracted from Waste Tire

Concrete pavements offer a sustainable alternative to asphaltic pavements in road construction due to increasing asphalt prices and environmental concerns. Steel fibers are utilized for reinforcing concrete pavements to improve tensile strength and post-cracking behavior, enhancing overall concrete performance. However, the cost and construction method serve as significant obstacles to their widespread adoption. A promising and eco-conscious solution is found in the use of recycled steel fibers sourced from post-consumer tires, providing both cost-efficiency and environmental benefits. A comprehensive understanding of the mechanical properties of recycled steel fiber-reinforced concrete (RSFRC) is essential before incorporating this material into practical infrastructure. Therefore, experimental and numerical investigations were carried out using 0.5, 1.5, and 2.25% RSF to evaluate the maximum load-carrying capacity of the concrete pavement section. In the experimental phase, compressive strength, split tensile, and flexural tests were performed on RSFRC specimens including cylinders and beams. In the numerical investigation, fracture-plastic constitutive models of concrete pavement sections were developed in ATENA employing the experimental results as an input. The experimental findings indicated that specimens containing 1.5% RSF exhibited the most favorable strength outcomes. These specimens experienced significant enhancements, with a respective increase of 10.7% in 28-day compressive strength, 39.3% in split tensile strength, and 10.4% in flexural strength compared to the other specimens tested. A number of numerical models of concrete pavement sections were developed, encompassing a variety of materials, including plain cement concrete (PCC), PCC with steel wire mesh, RSFRC, and RSFRC with steel wire mesh. These models also incorporated varying dimensions as well as soil compaction properties. Based on the numerical analysis, it was determined that when compared to the PCC pavement section, the load-carrying capacity increased by 17% for the RSFRC pavement section, 32% for the PCC with steel wire mesh pavement section, and a substantial 154% for the RSFRC with steel wire mesh pavement section. Moreover, a cost analysis and an evaluation of environmental benefits were carried out, and the results, along with the design recommendations, are presented.