| 摘要 |
PURPOSE:To improve handleability by adding a synthetic polymer-based emulsion and kneading water to a composition consisting of portland cement, quartz sand and a lightweight aggregate in a specified weight ratio, kneading the mixture and placing the kneaded material in a formwork to obtain a formed body. CONSTITUTION:The cement composition is obtained by mixing 45-65wt.% portland cement, 0-30wt.% quartz sand (No.6 to No.8), 15-35 wt.% lightweight aggregate such as calcined obsidian having about 0.3-0.4g/cm<3> bulk density, 0.5-1.0wt.%, based on cement, of a high-performance water-reducing agent and 0.05-0.2wt.%, based on cement, of a thickener such as methylcellulose. From 5 to 10 pts.wt. of a synthetic polymer emulsion such as an acrylic emulsion and 30-45 pts.wt. of water are added to 100 pts.wt. of the composition, mixed and kneaded. The kneaded material is placed in a formwork about half full, the remaining kneaded material contg. wire, etc., is then placed, and the surface is roughened. The mixture is allowed to stand for several days, and then the formwork is removed to obtain the lightweight-aggregate concrete coping. |
