| 摘要 |
PURPOSE:To provide a cement admixture, etc., giving an excellent fluidity when a concrete is deposited into a mold frame while decreasing the fluidity rapidly after deposited and decreasing a side pressure forced on the mold frame of concrete by speeding up the hardening. CONSTITUTION:The cement admixture contains as the effective components one kind or more than two kinds of a component alpha selected from the group of magnesium sulfates, aluminum sulfates and calcium aluminates and a thickener and/or a water reducing agent. Or, the cement admixture contains as the effective components the component alpha and one kind or more than two kinds of a component beta selected from among the group of boric acids, bentonite, limes, and gypsums and a thickener and/or a water reducing agent, or moreover, the cement composition is composed of a cement and the cement admixture. |
