铸造粉尘-粉煤灰基地质聚合物的力学性能和微观结构分析

Mechanical Properties and Microstructure Analysis of Casting Dust-Fly Ash Based Geopolymer

以粉煤灰为主要原料,以铸造粉尘为掺合料,水玻璃溶液为碱激发剂,制备地质聚合物。研究了养护龄期和水灰比对铸造粉尘-粉煤灰基地质聚合物抗压强度的影响。结果表明,铸造粉尘-粉煤灰基地质聚合物的抗压强度随养护龄期的延长而增大,随水灰比的增大先增大后减小;当水玻璃模数为1.2,水灰比为0.4时,地质聚合物28 d抗压强度达到最大,为21.4 MPa。X衍射分析表明,形成的地质聚合物主要为无定形矿物相;红外光谱分析表明,地质聚合物中有较多的非晶态铝硅酸盐生成;SEM分析显示地质聚合物具有良好的致密结构。

Casting dust-fly ash based geopolymer has been synthesized by using fly ash as main raw material,casting dust as admixture,water glass solution as activator.The effects of curing age and water cement ratio on compressive strength of casting dust-fly ash based geopolymer were studied.The result showed that the compressive strength increased with the passage of curing age and increased firstly and then decreased with the water cement ratio increasing.When the modulus of water glass solution was 1.2 and the water cement ratio was 0.4,the 28 d compressive strength was 21.4 MPa.The XRD results demonstrated that the phase structure of geopolymer took the shape of amorphous phase.IR showed that geopolymer contained many amorphous aluminosilicates.SEM images indicated that geopolymer displayed obviously dense microstructure.