低水膏比时减水剂对β半水脱硫石膏力学性能的影响

Effect of Superplasticizer on the Mechanical Properties of Beta-half-water FGD Gypsum under Lower Ratio of Water to Gypsum

研究了低水膏比时减水剂对β半水脱硫石膏力学性能的影响。结果表明:脱硫石膏脱水工艺最佳参数为烘干温度170℃,烘干时间6 h和陈化时间5 d。显微结构表明,β半水脱硫石膏颗粒表面为粗糙、不完整结构;烘干时无水石膏与半水石膏同时存在才具有较高的强度。当水膏比为0.28,减水剂掺量为0.9%～1%时,β半水脱硫石膏抗压强度达到最大值35 MPa,在此掺量下减水剂可有效减少成型时需水量和提高试块强度。

The effect of superplasticizer on the mechanical properties of beta-half-water FGD under lower ratio of water to gypsum was investigated. The testing results showed that the gypsum optimum parameters for the dehydration process of FGD gypsum are drying temperature is 170 ℃, drying time is 6 h,and aging time is 5 d. By investigating microstructure, it has been indicated that the particles surface of the beta-half-water FGD gypsum is rough and incomplete; the strength of dehydration FGD gypsum is higher when the anhydrite and hemihydrate gypsums have co-existed under the condition of drying. When the ratio of water to gypsum is 0.28 and superplasticizer dosage is 0.9% -1%, the maximum compressive strength of beta-half-water FGD gypsum reaches 35MPa which can be explained that using this dosage superplasticizer can effectively reduce the water requirement water to molding so it can improve the strength of testing block.