铸造旧砂蒸压砖的研制

以铸造旧砂和粉煤灰、石硝为主要原料,添加一定量的消石灰和复合外加剂,经轮碾、压制、蒸压等工序所制备的蒸压砖的质量符合GB11945-1999中MU15要求,放射性核素符合GB6566-2001中建筑主体材料要求,碳化系数和干燥收缩值符合JC 239-2001粉煤灰砖要求。对铸造旧砂、粉煤灰和铸造旧砂蒸压砖样品的浸出毒性监测结果表明,所有危险物质浓度均低于GB5085.3-1996中最高允许浓度。通过SEM和XRD分析对铸造旧砂蒸压砖强度形成机理进行了探讨。铸造旧砂蒸压砖价格会比普通灰砂砖低,将会具有较好的市场前景。

Development of Autoclaved Bricks from Waste Foundry Sand

An autoclaved brick has been prepared from waste foundry sand,crashed stone and fly ash,with addition of suitable amount of activators,such as hydrated lime and special composite.The preparation process comprises wheel-rolling blending,molding with high pressure and autoclaved curing process.Autoclaved bricks have been tested by authoritative testing department.The results show that the strength reaches the standard of 15C(GB11945-1999);and radium activity concentrations are lower the limit in main building materials(GB6566-2001);the coefficient of carbonization and the data of drying shrinkage accord with Chinese fly ash brick standard(JC 239-2001).Moreover,the leaching toxicity results of waste foundry sands,fly ash and autoclaved bricks are lower than the standard of GB5085.3-1996.The strength forming mechanism is investigated by XRD and SEM Techniques.Cost of autoclaved brick made from waste foundry is lower than that of traditional autoclaved brick,which shows potential application market.