EFFECTS OF ANTIFREEZING ADMIXTURE AND AGGREGATE QUALITY ON CONCRETE UNDER COLD ENVIRONMENT

摘要

The compressive strength and the freezing and thawing durability of concrete was studied using mixed crushed sand, low quality land sand, and two chemical admixtures, namely, air entraining agent (AE) and antifreezing admixture (NF). NF concrete, cured in the field under the cold weather, indicated higher increase of the compressive strength rather than the field-cured AE concrete. However, the field-cured NF concrete with frost damage below 0℃ in early age during the curing period, indicated not only less increase of the compressive strength but also a half compressive strength of the standard-cured NF concrete without frost damage. Furthermore, the concrete using low quality aggregate had durability problem despite compounding NF into cold weather concrete.