无机外加剂提升脱硫石膏耐水性能研究

THE STUDY ON INORGANIC ADDITIVE IMPROVING WATER RESISTANCE OF FGD GYPSUM

脱硫石膏制品普遍存在遇水后强度下降很快的缺陷,严重制约其使用功能。以铝酸盐水泥和普通硅酸盐水泥按一定比例配制而成的无机外加剂掺入脱硫石膏中,改善脱硫石膏的耐水性能,研究不同外加剂掺入量条件下脱硫石膏的力学性能和耐水性能的变化规律。结果表明,与不加外加剂相比,当掺入5%的外加剂时,脱硫石膏的吸水率为0.23,降低了23.33%;脱硫石膏的绝干、吸水饱和抗压强度分别为21.25MPa和9.43 MPa,脱硫石膏的抗折、抗压软化系数分别为0.49和0.44,分别提高了16.94%、39.30%、23.25%、37.60%。

The FGD gypsum product generally has the drawback of rapid decline in strength after meeting water , which seriously limits its using function. The inorganic additive consisting of aluminate cement and ordinary Portland cement was put into FGD gypsum for improving the water resistance of FGD gypsum. Then the changes of mechanical properties and water resistance of FGD gypsum under dif- ferent additive conditions are studied. The results showed that when the dosage of the additive is 5%, the water absorption rate of FGD gypsum is 0. 23, which is 23.33% lower than no additive; the compressive strength of dry and saturated water are 21.25 MPa and 9.43 MPa respectively; the flexural and compressive softening coefficients are 0. 49 and 0. 44 , improving 16. 94%, 39.30%, 23.25% and 37.60% respectively, compared with no additive.