不同掺量铁尾矿对3D打印混凝土胶凝材料性能的影响

Effect of Iron Tailings with Different Content on the Properties of 3D Printing Concrete Cementitious Materials

这是一篇陶瓷及复合材料领域的论文。本文研究了掺铁尾矿3D打印胶凝材料的力学性能、流变性和微观结构性能,结果表明:尾矿的粒径较小,可以作为3D打印材料的骨料,在3D打印过程中可以顺利通过输送胶凝材料的管道。随着铁尾矿掺量的不断增大,3D打印胶凝材料的剪切黏度的变化规律呈现出先减小后稳定的趋势,剪切应力的变化规律却呈现出不断增大的趋势,随着层间间隔时间不断增大,3D打印胶凝材料的抗压强度和抗折强度均呈现下降的变化趋势,但是在层间间隔时间在20~30 min之间时,抗压强度和抗折强度下降幅度较为平缓;随着层间间隔时间不断增大,3D打印胶凝材料的层间粘结强度均呈现下降的变化趋势。铁尾矿掺量为30%的3D打印胶凝材料在水化90 d后,经过XRD衍射实验得到胶凝材料的物质成分主要有石英、钙矾石、方解石、钠长石、钙钛矿、Ca_(2)SiO_(4)和水化硅酸钙等七种物质。

This is an article in the field of ceramics and composites.Rheology and microstructure properties of iron-doped tailings 3D printing cementitious materials were studied in this paper.The results show that the particle size of tailings is small and can be used as aggregates for 3D printing materials.In the 3D printing process,it can smoothly pass through the pipeline for conveying the cementitious material.As the content of iron tailings continues to increase,the shear viscosity of 3D printing cementitious materials shows a trend that first decreases and then stabilizes in the region.However,the changing law of shear stress shows an increasing trend as the interval between layers increases.The compressive strength and flexural strength of 3D printing cementitious materials both show a decreasing trend.When the interval between layers is in between 20~30 min,the compressive strength and flexural strength decrease more slowly.As the interval between layers continues to increase,the interlayer bonding strength of 3D printing cementitious materials shows a decreasing trend.The 3D printing cementitious material with 30%iron tailings content is hydrated for 90 days after XRD diffraction test.The main material components of the cementitious material are quartz,ettringite,calcite,albite,perovskite,Ca_(2)SiO_(4) and seven substances such as calcium silicate hydrate.