PVA纤维对纳米水泥基复合材料单轴拉伸性能的影响

为研究PVA纤维掺量对掺纳米SiO_2水泥基复合材料抗拉性能的影响,通过单轴拉伸试验测得了试件的极限拉伸应变和极限拉伸应力,并得到了试件应力—应变关系曲线。纳米SiO_2的质量掺量为2%,PVA纤维采用五种体积掺量(0.3%、0.6%、0.9%、1.2%、1.5%)。结果表明,PVA纤维的掺加增大了纳米水泥基复合材料单轴拉伸试件的极限拉应变和极限拉应力。当PVA纤维体积掺量不大于1.5%时,随PVA纤维掺量的增大,试件极限拉应变逐渐增大,极限拉应力先增大后减小。当PVA纤维体积掺量分别为1.5%、1.2%时,试件极限拉应变和极限拉应力分别达到最大值;PVA纤维水泥基复合材料中掺加2%纳米SiO_2后,整体上提高了试件的极限拉应力,但试件极限拉应变变化不明显,纳米SiO_2使PVA纤维增强水泥基复合材料的抗拉伸性能得到了进一步提高。研究成果可为工程应用提供指导。

Effect of PVA Fiber on Uniaxial Tensile Properties of Cement Based Composites Incorporating Nano-materials

Ultimate tensile strain and ultimate tensile stress of the specimens were measured through uniaxial tensile tests to investigate the effect of PVA fiber on the uniaxial tensile properties of cement based composites incorporating nano-materials. Stress-strain relationship curves of the specimens were obtained. The nano-particle content was adopted as 2%. Five volume contents of PVA fiber (0.3%, 0.6%, 0.9%, 1.2%, and 1.5%) were designed. The results show that the addition of PVA fibers increases the ultimate tensile strain and ultimate tensile stress of the specimens of cement based composites containing nano-particles. When the volume content of PVA fibers is below 1.5%, the ultimate tensile strain increases gradually, and the ultimate tensile stress increases first and then has a trend of decrease with the increase of PVA fiber volume content. The ultimate tensile strain and ultimate tensile stress of the specimen reach the maximum when PVA fiber volume content is 1.5% and 1.2%, respectively. With the addition of 2% nano-SiO2 in PVA fiber reinforced cement based composites, the ultimate tensile stress of the specimen can be greatly improved, while there is no obvious change in the ultimate tensile strain. The addition of nano-SiO2 has significant improvement in tensile properties of PVA fiber reinforced cement based composites. The results of this study can provide guidance for engineering applications.