PURPOSE: To obtain superhigh-strength concrete by performing hydration reaction of cement and water while exerting high pressure and adding an admixture such as AE agent and a retardant to cement and water and also kneading this mixture in the low-temp. environment and placing the kneaded substance into a frame mold and thereafter exerting necessary pressure and aging this kneaded substance.

CONSTITUTION: Hydration reaction of cement and water is performed while exerting high pressure. An admixture such as an AE agent and a retardant is added to cement and water. Furthermore various materials for concrete preserved at low temp. are kneaded in the low-temp. environment and this kneaded substance is placed into a frame mold and thereafter necessary pressure is exerted and the kneaded substance is aged. Therefore a gap between crystals of cement paste is collapsed by pressure and reduced. The contact area between crystals is made great and bonding force is enhanced. Thereby dispersion of crystal in cement paste is made little and cement paste is made dense. Superhigh-strength concrete is obtained which has compression strength higher than high-strength concrete.