Abstract
Studies were made on cases of using blast-furnace slag sand and of using air entrainment as methods of improving freezethaw resistance of extremely stiff-consistency concrete for instant stripping. The results show that there is considerable variation in resistance depending on the variety of slag sand, while stable resistance is obtained with air-entrained concrete. A method of measuring entrained air out of the air content of concrete was studied for extremely stiff-consistency air-entrained concrete, the reliability of the method was ascertained, and the conditions for selecting air-entraining agents suitable for extremely stiff-consistency concrete were examined.
