| 摘要 |
PROBLEM TO BE SOLVED: To suppress the influence of shrinkage due to expansion and dryness caused by temperature increase on concrete.SOLUTION: A substance (negative expansion substance) shrunk in accordance with the increase of the temperature of cement by hydration reaction is mixed with cement, water and an aggregate. As the negative expansion substance, e.g., A site-order type perovskite oxides such as aluminum titanate and manganese-nitrogen compounds can be given. Further, the negative expansion substance may be the one having no reverse-perovskite structure, and may be various kinds of amorphous inorganic substances. In this case, the amorphous glass is heated to a temperature exceeding a glass transition point and is crystallized, thus may be shrunk in accordance with the increase of the temperature. As the negative expansion substance, in the case a manganese-nitrogen compound having a reverse perovskite structure is used, the volume of the negative expansion substance occupied in the mixture obtained by the mixture is desirably 1 to 2%.SELECTED DRAWING: None |
