| 摘要 |
PURPOSE:To decrease specific gravity and water absorptivity of a molding and to improve strength and weatherability by flask-forming a mortal containing a lightweight aggregate of prescribed ratio in a composition specifying alumina cement, alkali stearate, zirconia or the like. CONSTITUTION:The concrete composition is obtained by flask-molding a mortal composition containing composition A of 1 pts.vol., an aggregate of 2-4 pts.vol., water of 25-35 pts.wt. (per the composition A to 70 pts.wt.). The composition A consists of at least one kind selected the group consisting of alkali salts of stearic acid and/or alkali earth metal salt of stearic acid of 0.5-3wt.%, zirconia and/or magnesia of 0.5-10wt.%, and alumina cement of 99.5-87wt.%. The concrete composition is low in specific gravity and water absorptivity and excellent in strength and weatherability. |
