| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress a reduction in early strength and improve workability of concrete using fly ash as an admixture to promote the practical use thereof.SOLUTION: In using fly ash as an admixture for concrete, 10 to 40% (preferably 20 to 30%) of the total volume of coarse aggregate or fine aggregate is substituted with artificial aggregate of clay fired at high temperature such as waste roof tiles. The early strength equivalent to that of ordinary concrete can be obtained with a low water-to-cement ratio (15 to 30%) using less amount of mixing water. In contrast, good workability is obtained with a high water-to-cement ratio (30 to 55%), which results in extremely high fluidity.</p> |
