FROST ACTION ON IMMATURE CEMENT PASTE - EFFECTS ON MECHANICAL BEHAVIOR.

Application of a limited number of freezing and thawing cycles to cement paste at a very early stage of hydration induced effects that were not apparent for slightly more hydrated samples. Irreversible deterioration in strength and in fracture toughness were recorded. The effect of air entrainment, however, was shown not to be confined to retarding degradation caused by frost action. Early freezing of air-entrained paste actually had a beneficial effect on the final strength and fracture behavior of the material.