Abstract:To investigate the performance evolution of steel fiber reinforced concrete （SFRC） under the coupling of chloride and freeze-thaw dry-wet cycles， the damage and deterioration of SFRC were treated by chloride freeze-thaw cycles. The chloride transport， pH value distribution， compressive strength and flexural strength of the freeze-thaw damaged SFRC exposed to chloride dry-wet cycles（DW） were investigated. The results indicate that the internal chloride content of freeze-thaw damaged SFRC increases and the near-surface pH value decreases under chloride DW， implying potential corrosion risks. However， after 180 times of chloride DW， the compressive strength and flexural strength of freeze-thaw damaged SFRC specimens increase by 8.7%-19.4% and 10.2%-29.7%， respectively， and their flexural toughness and stiffness also improve significantly. The continuous hydration of cementitious materials repairs the damage of SFRC induced by freeze-thaw cycles under chloride DW. Moreover， the positive reinforcement effect of steel fiber corrosion （interface strengthening and crack filling） further improves the mechanical properties of concretes.
