Abrasion resistance of milling steel fiber-reinforced ultra-high-performance concrete under various wearing conditions

Ultra-high-performance concrete (UHPC) is susceptible to various forms of abrasion during its service life. This study investigates the abrasion resistance of UHPC by focusing on two primary causes of wear: traffic dynamic loads and hydraulic impacts. To enhance the material's resistance to abrasion, milling steel fibers were utilized, and for comparative purposes, straight steel fibers and hybrid milling-straight steel fibers were also employed. The protective function of the steel fibers primarily comes into effect once the concrete cover has experienced wear. When subjected to traffic and hydraulic loads, UHPC containing milling fibers exhibited superior resistance compared to that containing straight fibers, while maintaining favorable workability. Notably, the UHPC incorporating hybrid steel fibers, which form a composite skeleton due to the presence of two fiber types, demonstrated even greater effectiveness in resisting external abrasion. Furthermore, the abrasion resistances observed under both traffic and hydraulic conditions displayed a positive linear correlation with an R² value exceeding 0.8. These findings suggest the feasibility of evaluating the material's abrasion resistance under various wearing causes using a single test method. The outcomes of this study hold promise in advancing the development of UHPC and promoting its utilization in conditions characterized by severe abrasion.