| 摘要 |
PROBLEM TO BE SOLVED: To improve sticking property and winding property by adding a water reducing agent, a thickener and water into a mixture with a specific ratio of Portland cement and natural pumiceous sand fine aggregate, kneading the mixture and adjusting viscosity to a specific range. SOLUTION: The Portland cement and the natural pumiceous sand fine aggregate are mixed in the ratio of 1:0.5 to 1:1.5. A mortal composition for spraying is formed by adding the water reducing agent, the thickener and water into the mixture, kneading the mixture and adjusting the viscosity to 100,000-20,000 cP/20 deg.C. The max. particle diameter of the natural pumiceous sand is 3 mm and one having <=0.3 mm particle diameter is desirably contained by 40-60 wt.%. The pumiceous sand fine powder can be added in a ratio by weight of <=0.5 to the Portland cement in place of a part of the Portland cement. The Blaine specific surface area of the pumiceous sand fine powder is desirably >=5000 cm2/g. The water reducing agent is desirably a high grade AE water reducing agent and, for example, polyacrylic acid, polymethacrylic acid, or the like, is cited. |
