PROBLEM TO BE SOLVED: To provide a steam aging method for steel slag which enables risk of delayed expansion of the steel slag to be removed, thereby enabling the steel slag to be used for subbase material and aggregate at a high blending ratio as the slag having high reliability in expansion stability.SOLUTION: The steam aging method for steel slag is provided in which expansion of steel slag is suppressed for stabilization. The steel slag is subjected to a plurality times of steam aging processing with a weight loading step interposed between them. As a referable example, first steam aging for rising and maintaining temperature of the steel slag is carried out, and then the steel slag after the first steam aging is subjected to weight loading and second steam aging for rising and maintaining temperature again is carried out.SELECTED DRAWING: Figure 3
