矿物掺合料与化学外加剂对3D打印砂浆性能的影响

研究了矿物掺合料与化学外加剂对3D打印砂浆流变性能、凝结时间及打印性能的影响.结果表明:复掺矿粉与硅灰可显著改善打印砂浆的流变性能,延长打印砂浆的可操作时间,提高打印砂浆的打印性能;随着减水剂掺量的增加,打印砂浆的黏度、屈服应力及触变性均逐渐降低,凝结时间延长,减水剂掺量过低或过高均会对打印砂浆的打印性能产生不利影响;掺加适量缓凝剂可降低打印砂浆的黏度和屈服应力,改善其挤出性;随着石膏掺量的增加,打印砂浆的表观黏度、屈服应力、触变性及有效打印高度均呈现先降后增趋势,而挤出性变化规律与之相反.

Effect of Mineral Admixtures and Chemical Admixtures on Performance of 3D Printing Mortar

The effect of mineral admixtures and chemical admixtures on the rheological behavior, setting time and printability of 3D printing mortar was studied. The results show that the addition of blast furnace slag and silica fume can significantly improve the rheological properties, prolong the operating time and printability of 3D printing mortar. With the increase amount of water reducing admixture, the viscosity, yield stress and thixotropy of 3D printing mortar are reduced, and the setting time is prolonged. However, too low dosage or too high dosage of the water reducing admixture will adversely affect the printability of 3D printing mortar. By adding appropriate retarder the viscosity and yield stress of 3D printing mortar can be reduced and its extrudability can be improved. With the increased dosage of gypsum, the apparent viscosity, yield stress, thixotropy and effective printing height of 3D printing mortar first decrease and later increase while the performance of extrudability shows the opposite.