研究期間：10108~10207;This two-year project plans to study the expansive behavior of recycled materials contained sintered silica, such as waste glass, waste tile, sintered light aggregate, and slag, used as the aggregate in concrete. The expansion of this kind recycled material may result from the alkali-aggregate reaction due to the amorphous silica contained in the material act as reactive aggregate, or from the slow hydration of hard burned calcium oxide or magnesium oxide. In the first year, this research plans to investigate the reactivity of the recycled materials according to ASTM C289, C227 and C1260, exam the pessimum effect of content and particle size of the identified reactive materials, and study the strategy for preventing expansion. In the second year, the slow hydration of CaO and MgO contained in the slag will try to be accelerated by breaking to the range of sand and cured in the moist environment. A mortar bar expansion test will be developed to identify the stability of slag on expansion. The expansive behavior of mortar bar samples will test in the conditions of 150℃ autoclave chamber, 100℃ steamed case and boiling water. The relationship among the slag particle size, temperature and curing time will be established in the process of slag stabilization.