The goals of this paper are to study the frost resistance of steel slag fine concrete(SSFC),re-search the damage mechanisms in cold regions.First,the mass loss rate,strength loss rate,relative dynamic elastic modulus of concrete with different steel slag fine aggregate replacement rates after freezing-thawing cycles were tested,and the freezing-thawing damage law was analyzed.Scanning electron microscopy meth-od was used to observe the hydration products of steel slag concrete and the steel slag-mortar interface transition zone for the analysis of freezing-thawing damage microscopic mechanisms.The results revealed that the steel slag fine aggregate is significantly damaged by freezing-thawing action.Interfacial transition zone of steel slag fine concrete is superior to that of ordinary concrete.The minimum mass and strength loss of concrete at 60%replacement rate of steel slag fine concrete,only 4.06%and 44.2%reduction,re-spectively.The highest mass and strength loss rates of concrete are 6.05%and 58%,respectively,with 100%replacement of steel slag fine concrete.When the number of freeze-thaw cycles is greater than 50,the relative dynamic elastic modulus of concrete with 60%of steel slag fine concrete is higher than the rest of the dosing group.In order to improve the performance of concrete under freezing-thawing cycles,60%replacement rate of steel slag fine concrete is recommended.Finally,the freezing-thawing damage evolution model of steel slag concrete was established by analyzing the damage evolution s of steel slag concrete specimens.
steel slag concretehydration productsstrength lossrelative dynamic modulus of elasticitydamage model