The properties of high fluidity concrete with a combination of the fine powder of slowly cooled blast furnace slag and granulated blast furnace slag were examined. The change of slump flow value with time decreased when a specified ratio or more of slowly cooled blast furnace slag was used. The concrete with various levels of compressive strength can be prepared by changing the mixing ratio of these powders. It has been clarified that close relations exist between adiabatic temperature rise and the unit weight of binder, as well as between autogenous shrinkage and water binder ratio, and that mix proportion design suited to required performance is possible. By the use of this high fluidity concrete, it is possible to suppress both CO2 emission and limestone consumption per unit of concrete, which suggests that this concrete is useful from the viewpoint of reduction in environmental burden.
