| 摘要 |
PROBLEM TO BE SOLVED: To provide a concrete composition which has good handleability and can be packaged, and whose quality is kept constant; and to provide a hardened concrete formed by adding water to the concrete composition and kneading them, the hardened concrete having lightweight properties and non-shrinkage properties and being applicable for civil engineering and construction structures having a middle-or-larger cross-sectional surface.SOLUTION: An aggregate contained in the concrete composition comprises at least a middle aggregate, wherein the middle aggregate is shown by a grading curve covered in a range surrounded with a grading curve showing a lower limit of a fine aggregate and a grading curve showing an upper limit of a coarse aggregate, among grading curves drawn in a graph where a first axis shows a dimension of a sieve and a second axis shows a weight percentage of a passed aggregate, which then shows the weight of an aggregate passed through the sieve to the weight of shifted aggregates. The concrete composition does not contain the coarse aggregate having a fineness modulus (FM) larger than the middle aggregate. |
