Abrasion resistance of concrete under coupled debris flow and freeze-thaw cycles

Abstract

In cold regions, the coupled actions of freeze-thaw cycles and debris flow abrasion cause severe deterioration of concrete structures. The effects of freeze-thaw cycles (0, 10, 30, 50, 70), debris flow velocities (2.5 m/s, 3.0 m/s, 3.5 m/s), and abrasion modes (abrasion-freeze, freeze-abrasion) on the abrasion resistance are investigated in this study to enhance the anti-abrasion performance of concrete. Abrasion rate, abrasion depth, abrasion morphology, and abrasion failure mechanism of concrete are discussed. The results show that the abrasion resistance of concrete decreases with the increase of debris flow velocities and freeze-thaw cycles. The abrasion failure degree of concrete is exacerbated by freeze-thaw cycles. The abrasion rate of the reference concrete (R) increases by 62.5–117.7% after 70 freeze-thaw cycles, compared to the unfrozen concrete. Furthermore, the freeze-abrasion mode loses more strength and mass loss than the abrasion-freeze mode, particularly at high freeze-thaw cycles. When compared to the mass loss caused by freeze-thaw cycles, abraded mass loss is the primary cause of concrete mass loss under coupled freeze-thaw cycles and debris flow abrasion. Due to improved mechanical strengths, steel fibre-reinforced concrete performs well under coupled freeze-thaw cycles and debris flow abrasion conditions.