METHOD FOR DETERMINING UNIT AMOUNT OF EXPANSIVE ADDITIVE OF CONCRETE STRUCTURE

PROBLEM TO BE SOLVED: To provide a method for determining the unit amount of an expansive additive of a concrete structure by which a crack caused by drying shrinkage becoming an initial defect in a surface member constituting the structure such as a slab or wall in which the crack caused by the drying shrinkage is especially remarkable, is inhibited or prevented.SOLUTION: The method for determining the unit amount of an expansive additive is applied for determining the unit amount of an expansive additive of a concrete structure obtained by placing a concrete material containing low heat-generation cement, a low-addition type ettringite-lime composite expansive additive, aggregate and water. In the method, the optimal unit amount Y of the expansive additive is determined by using a relational expression of the predetermined water ratio X and the unit amount Y of the expansive additive, for each predetermined temperature range.