EXPERIMENT OF PROPERTIES DETERIORATION OF CONCRETE IN MULTI-AGGRESSIVE AND FREEZE-THAW ENVIRONMENT

With mass fraction of 3% sodium chloride and 5% sodium sulfate mixed solution as aggressive medium, by adopting slow freeze-thaw method, freeze-thaw tests of freeze-thaw cycles of being 100, 200 and 300 were carried out on concrete specimens.The cubic compressive strength was 54.7MPa.The mass loss, compressive strength, relative dynamic modulus, strain and stress were tested.The results show that with the increase in freeze-thaw cycles, increased erosion of concrete specimen surface and the apparent quality and relative dynamic modulus did not change significantly when both of compressive strength and elastic modulus decreased a lot.Compressive strength and elastic modulus decreased by 26% and 35.1% after 300 freeze-thaw cycles.