| abstract |
To provide a concrete composition, while suppressing the exhaust amount of carbon dioxide, which can secure satisfactory applicability in a state where the reduction in the fluidity and the reduction in an air amount with the lapse of time in a prepared concrete composition are suppressed, further can suppress the drying shrinkage of the obtained hardened body, and can make the required strength appear in the obtained hardened body. The blast-furnace slag composition at least comprises a binder, water, fine aggregate, coarse aggregate and an admixture. As the binder, the following blast-furnace slag composition is used, and also, the mass ratio of the water/the blast furnace slag composition is adjusted to 30 to 60%. Per 100 pts.mass of the mixture including a blast furnace slag composition comprising blast-furnace slag fine powder whose fineness is 3,000 to 13,000 cm2/g by 80 to 95 mass and gypsum by 5 to 20 mass% (total 100 mass%), an alkali activator is added in a ratio of 0.5 to 1.5 pts.mass or 5 to 45 pts.mass. |