Abstract
The cement industry has exhausted a lot of CO2. It is effective method for reduce CO2 during cement production to replace blast-furnace slag to cement. In this study we investigate the reaction and the microstructure in cement containing more than 70％ blast-furnace slag. We analyze blast-furnace slag（BFS）-Anhydrate（CS）-ordinary portland cement（OPC）system when change the addition ratio of CS and OPC. The hydration reaction in this type of cement are analyzed by measurement of heat of hydration by using sandwich calorimeter and reaction ratio of BFS, X-ray diffractometry and observation by SEM. This type of cement has positive correlation between heat of hydration and reaction amount of BFS. So measurement of heat of hydration is useful method for this type of cement. The hydrated cement products are ettringite and C-S-H. And they are same in all composition. Although we must optimize the addition ratio of OPC when use this type of cement. In the worst composition, ettringite make film-shaped structure, and it obstructs contact with water and BFS. The film-shaped structure is made in initial rapid hydration. The best composition is that BFS and CS ratio is 95：5, and add OPC 15w％. This composition has the highest reaction ratio and quality stability.
