| 摘要 |
PROBLEM TO BE SOLVED: To obtain excellent early strength by using cement, fine aggregates, coarse aggregates, a cement dispersant consisting of a water-soluble vinyl copoly mer containing structural units expressed by specified formulae and a hardening accelerator under the prescribed ratio thereof. SOLUTION: The cement dispersant of the water-soluble vinyl copolymer having 2000-20000 number average molecular weight which is polymerized methacrylic acid, methyl-methacrylate, etc., and whose structural units A-D expressed by formulae I-IV (R<1> , R<2> ; H, CH3 , R<3> ; phenyl, etc., M<1> , M<2> ; an alkali metal, etc.,), consist of 40-65mol.% A, by mol., 2-20% B, 5-20% C, and 10-40% D, is obtained. Next, 100 pts., by wt.,) early strength Portland cement, fine aggregates and coarse aggregates are mixed and subsequently are mixed with 0.3-1 pt. the cement dispersant, and 1.5-6 pts. hardening accerator of a Rhodan salt/nitrite mixture, etc., and water, and kneaded to obtain the ultrahigh early high strength concrete composition having a water/cement ratio of 20-40%, 120-185kg/m<3> unit water quantity, 500-900kg/m<3> fine aggregates and 800-1200kg/m<3> coarse aggregates. |
