Abstract: In order to study the durability of steel slag fine aggregate concrete(SSC)under the action of dry-wet cycle of salt solution, the optimal volume fraction of steel slag and fly ash in concrete was determined by mechanical property tests, and the dry and wet durability test of salt solution was carried out on concrete samples. The effects of the volume fraction of steel slag and fly ash on the appearance, quality, dynamic elastic modulus, and compressive strength of concrete were considered comprehensively. The results showed that when the volume fraction of steel slag was 30%, the compressive strength, flexural strength, and dynamic elastic modulus of SSC were better than those of ordinary concrete. The mechanical properties of SSC were further improved after 10% volume fraction of fly ash was added. After 100 dry-wet cycles of salt solution, the mass loss rate, compressive strength loss rate, and dynamic elastic modulus loss rate of steel slag with 30% volume fraction were smaller than those of ordinary concrete. The addition of 10% volume fraction fly ash could delay the deterioration of SSC durability, and the durability of SSC in dry and wet cycling of single salt solution was better than that of double salt solution. The damage evolution equation was established with the dynamic elastic modulus damage as the index, which could describe the deterioration of SSC properties under the dry-wet cycle of salt solution.

Key words: steel slag fine aggregate concrete, salt corrosion, dry-wet cycle, durability, damage evolution