Abstract: Concrete compositions including a binder, water, a fine aggregate, a coarse aggregate and an admixture are provided. The binder is formed with a blast-furnace slag composition including 100 mass parts of a mixture of 80-95 mass % of blast-furnace slag fine particles with fineness 3000-13000 cm2/g and 5-20 mass parts of gypsum for a total of 100 mass % and 0.5-1.5 mass parts or 5-45 mass parts of an alkaline stimulant. Such concrete compositions can maintain superior operability by reducing the discharged amount of carbon dioxide and the decrease with time in fluidity and air content of the prepared concrete compositions. They can also reduce the drying shrinkage of the obtained hardened objects and allow the obtained hardened objects to manifest necessary strength.