PVA纤维增强铁尾矿砂混凝土的3D打印力学性能研究

Study on the Mechanical Properties of 3D Printing of PVA Fiber Reinforced Iron Tailings Sand Concrete

为研究PVA纤维掺量为0%、0.25%、0.5%、0.75%、1%的铁尾矿砂混凝土的3D打印力学性能,基于灰色预测模型分析其流动度和打印高度对抗压强度和抗弯强度的影响大小。结果表明:3D打印PVA纤维增强铁尾矿砂混凝土的流动度范围在159~176 mm内;PVA纤维掺量为0.5%时,混凝土流动度最小;PVA纤维掺量为1%时,混凝土流动度最大;其打印模型总高度随水胶比的增大而增大,随PVA纤维掺量的增加而减小;PVA纤维掺量一定时,3D打印PVA纤维增强铁尾矿砂混凝土随水胶比的增大,抗压强度逐渐降低,但在一定的水胶比下,抗压强度随PVA纤维掺量的增加呈现显著降低趋势;3D打印试件的抗弯强度随水胶比的增大而减小,并随纤维掺量的增大而变化;3D打印试件的流动度对抗弯强度的影响大,3D打印试件的打印高度对抗压强度的影响大。

In order to study the mechanical properties of 3D printing of iron tailings sand concrete with PVA fiber content of 0%,0.25%,0.5%,0.75%,and 1%,the fluidity and printing height were analyzed based on the gray prediction model,compressive strength and bending resistance.The magnitude of the effect of strength.The results show that the fluidity of 3D printed PVA fiber reinforced iron tailings sand concrete is in the range of 159~176 mm.When the content of PVA fiber is 0.5%,the fluidity of the concrete is the smallest;when the content of PVA fiber is 1%,the fluidity of the concrete is the largest;the total height of the printed model increases with the increase of the water-binder ratio,and decreases with the increase of the PVA fiber content;when the PVA fiber content is constant,the 3D printing PVA fiber-reinforced iron tailings sand concrete increases with the increase of the water-binder ratio.However,at a certain water-binder ratio,the compressive strength shows a significant decreasing trend with the increase of the PVA fiber content;the flexural strength of the 3D printing specimen decreases with the increase of the water-binder ratio,and changed with the increase of fiber content;the fluidity of the 3D printing specimen has a great influence on the flexural strength,and the printing height of the 3D printing specimen has a great influence on the compressive strength.