| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compsn. which can decrease self shrinkage or dry shrinkage without supplying a curing water, which has little cracks and which develops high strength in a small number of processes by using a lightweight fine aggregate together with an aggregate having specified or higher dry specific gravity and compounding a cement and water into the aggregates. SOLUTION: This concrete compsn. contains a coarse aggregate having >=2.5 dry specific gravity, lightweight fine aggregate, cement and water. The coarse aggregate is not specified as far as it has >=2.5 dry specific gravity, and a coarse aggregate usually used such as crushed stone, blast furnace slag and river gravel can be used. As for the lightweight fine aggregate, a fine aggregate having <=1.8 dry specific gravity is used, and preferably a fine aggregate having >=15% porosity or a fine aggregate which can include water by >=10 % is preferably used. The material of the lightweight fine aggregate is not specified, and for example, an artificial lightweight fine aggregate such as expanding clay and calcined shale, or a natural lightweight fine aggregate such as lapilli and pumice can be used. The compounding ratio of the lightweight fine aggregate is preferably 300 to 600 kg/m<3> in the compsn. |
