AIR-PLACING CONCRETE COMPOSITION

摘要

PURPOSE: To suppress the separation of material such as the precipitation of aggregate and to obtain a concrete composition excellent in freezing damage resistance even when an antifoaming agent is added by mixing a hollow microbead and an antifoaming agent in a concrete composition contg. water-soluble cellulose ether. CONSTITUTION: This air-placing concrete composition contg. water-soluble cellulose ether is mixed with a hollow microbead and an antifoaming agent. The water-soluble cellulose ether is used to prevent the separation of material such as aggregate, and the nonionic one is preferably used. Alkylcellulose and hydroxyalkylcellulose are exemplified as the nonionic cellulose ether, and hydroxyalkylcellulose and hydroxyalkylalkylcellulose are especially preferable because of their excellent fluidity. The polymeric hollow microbead consists of a polymeric globular elastic film, and the diameter is controlled to <=200nm, preferably to <=50μm.