Study on Activation of Waste Clay Brick Powder

Abstract Recycling and recycling of construction waste is a hot research topic nowadays. In this paper, clay bricks in building waste are activated by physical method (grinding) and chemical method (alkali activation). The effects of fineness after grinding time, types and dosage of activator on the activity of waste brick powder are studied. The results show that with the increase of grinding time, the specific surface area of waste brick powder increases, and the activity coefficient of waste brick powder increases. When grinding time is 90 minutes, the activity index reaches 67%. When the specific surface area of waste brick powder is 467 m2/kg, the activity index of waste brick powder increases first and then decreases with the increase of calcium hydroxide content. When calcium sulfate dihydrate is added alone, the activity index of waste brick powder increases first and then decreases with the increase of calcium sulfate dihydrate content. When calcium hydroxide and calcium sulfate dihydrate are mixed together, the increase of activity index is better than that of calcium hydroxide and calcium sulfate dihydrate alone. The 4% calcium hydroxide + 3% calcium sulfate dihydrate composite system has the best activation effect on brick powder.