硅酸镁铝及静置时间对3D打印地聚合物砂浆流变性能的影响

Effect of Magnesium Aluminum Silicate and Rest Time on Rheological Property of 3D Printing Geopolymer Mortar

以粉煤灰、矿粉、石英砂为主要原材料,无水硅酸钠为碱激发剂,硅酸镁铝为专用外加剂,制备了粉煤灰基3D打印地聚合物砂浆(以下简称地聚合物砂浆),研究了硅酸镁铝掺量及静置时间对其流变性能的影响,并在最佳硅酸镁铝掺量和最适合静置时间条件下进行了3D打印上机试验.结果表明:地聚合物砂浆的流变性能随着硅酸镁铝掺量的增加而增加,且随着静置时间的增加总体呈增长趋势;采用宾汉(Bingham)流体模型和赫切尔-巴尔克(Herschel-Bulkley)流体模型拟合地聚合物砂浆的流变曲线后发现,上述2种模型的拟合度R^(2)均较高,综合考虑后认为,宾汉流体模型比赫切尔巴尔克流体模型更具优越性;掺加1.0%硅酸镁铝和10 min左右静置时间的地聚合物砂浆能够较好地适用于3D打印工艺,且打印效果良好.

Fly ash based geopolymer mortar for 3D printing(refered to as geopolymer mortar)was prepared with fly ash,slag powder and quartz sand as main raw materials,anhydrous sodium silicate as alkali activator and magnesium aluminum silicate as special additive.The effects of magnesium aluminum silicate dosages and rest time on rheological properties of geopolymer mortar were studied.The results show that the rheological properties of geopolymer mortar is improved with the increase of the dosages of magnesium aluminum silicate additive and rest time.It is found that fitting the rheological properties of geopolymer mortar with the Bingham model and the Herschel-Bulkley model,R^(2) of the two models is satisfied,but the Bingham model is better than that of the Herschel-Bulkley model from comprehensive consideration.The geopolymer mortar mixed with 1.0%magnesium aluminum silicate admixture and resting for about 10 min can obtain better printability and printing effect.