METHOD FOR HARDENING FRESH CONCRETE, FRESH CONCRETE AND WATER ABSORBING MATERIAL USABLE THIS METHOD

摘要

PURPOSE:To improve workability and chemical resistance by dispersing a water absorbing material obtd. by coating an absorbent with a specified coating material in fresh concrete, dissolving the coating material and absorbing water in the absorbent. CONSTITUTION:An absorbent (e.g. CMC) 1 having water absorbency and water retentivity, absorbing 500-1,000 times as much water as its dead weight and absorbing 300-400 times as much water as its dead weight in a satd. aq. cement soln. is coated with a coating material (e.g. polyacrylamide) 2 reacting with a component in fresh concrete and causing dissolution to obtain a water absorbing material. This water absorbing material is dispersed in fresh concrete, the coating material 2 is dissolved after concrete placing and water in the concrete is absorbed in the absorbent 1 to harden the concrete.