Testing of recycled fine aggregate concrete’s mechanical properties using recycled fine aggregate concrete and research on technology for highway construction

Abstract The rapid growth of transportation engineering has led to significant environmental challenges due to the accumulation of building waste and tailings. A promising solution is to utilize these materials to develop high-performance tailings recycled concrete (RFAC) for highway construction, promoting a green circular economy. This study advances existing research by exploring innovative mix design strategies and performance optimization techniques to enhance RFAC’s mechanical properties and industrial applicability. Specifically, this research investigates the effects of various iron tailings admixtures on the mechanical behavior and deformation characteristics of RFAC before and after carbonation, aiming to establish an optimal composition for transportation infrastructure. The materials used include iron tailings, recycled coarse aggregate, natural river sand, and 42.5-grade ordinary silicate cement. Unlike conventional approaches, this study emphasizes the influence of particle morphology and surface characteristics of laboratory-produced recycled fine aggregate, revealing its angular shape, rough texture, and larger specific surface area, which significantly impact fluidity, bulk density, and crushing value. Experimental results demonstrate that fiber type and tailings admixture ratio play a crucial role in improving RFAC’s slump, compressive strength, split tensile strength, and failure modes. Compared to previous studies, this research provides a more refined analysis of mix proportioning and introduces tailings-based performance enhancements, offering new insights for large-scale applications in transportation engineering. By optimizing tailings incorporation and aggregate proportions, this study establishes a systematic approach to improving RFAC’s mechanical performance, durability, and construction adaptability, laying the foundation for sustainable infrastructure development.