| 摘要 |
PROBLEM TO BE SOLVED: To provide a cement admixture for steam curing which is effective for suppressing temperature cracks when demolding a concrete secondary product cured with steam and which does not exert bad influences on demolding strength because of not being accompanied by setting retardation and to provide a cement composition. SOLUTION: The cement admixture for steam curing contains an expansive material including an expansive substance being a core material encapsulated with a capsule wall material and an expansive material not encapsulated, the expansive material containing free line and anhydrous gypsum, or containing one or more kinds of hydraulic compounds selected from the group consisting of free line, hauyne, calcium silicate, calcium ferrite and calcium aluminoferrite. Furthermore, the cement admixture for steam curing may contain the free lime, the hydraulic compounds and anhydrous gypsum. The cement composition contains cement and the cement admixture for steam curing. COPYRIGHT: (C)2010,JPO&INPIT |
