PVA纤维和纳米SiO_(2)对水泥基复合材料性能影响研究

Effects of PVA fiber and nano-SiO_(2)on the properties of cementitious composites

通过复掺PVA纤维和纳米SiO_(2)到水泥基复合材料中,研究不同PVA纤维掺量(1.0%、1.5%、2.0%)和纳米SiO_(2)掺量(1.0%、1.5%、2.0%)下水泥基复合材料的抗折性能、抗压性能和抗硫酸盐侵蚀性能,并利用SEM扫描电镜分析了水泥基复合材料的微观形貌,探讨了PVA纤维和纳米SiO_(2)对各方面性能的作用机理。结果表明:水泥基复合材料的28 d抗折强度和抗压强度均随着PVA纤维体积掺量和纳米SiO_(2)掺量的增加逐渐增大,当二者掺量均为2.0%时,抗折强度最高为11.34 MPa,抗压强度最高为70.2 MPa。随着PVA纤维体积掺量和纳米SiO_(2)掺量的增加,水泥基复合材料干湿循环后的质量损失率逐渐减小,抗压强度耐蚀系数逐渐增大,当PVA纤维体积掺量和纳米SiO_(2)掺量均为2.0%时,质量损失率最低为0.827%,抗压强度耐蚀系数最高为0.995。

By mixing PVA fibers and nano-SiO_(2)into cementitious composites,the flexural properties,compressive properties and sulfate corrosion resistance of cementitious composites with different PVA fiber content(1.0%,1.5%,2.0%)and nano-SiO_(2)content(1.0%,1.5%,2.0%)were studied.At the same time,the micro-morphology of cementitious composites and the micro-action mechanism of PVA fibers and nano-SiO_(2)were analyzed by scanning electron microscope(SEM).The results show that the 28 d flexural strength and compressive strength of cementitious composites both increase gradually with the increasing of PVA fiber volume and nano-SiO_(2)content.When the contents are both 2.0%,the highest flexural strength is 11.34 MPa,and the highest compressive strength is 70.2 MPa.With the increasing of PVA fiber volume and nano-SiO_(2)dosage,the mass loss rate after the dry and wet cycles of the cementitious composite is reduced,and the corrosion resistance coefficient of the compressive strength is increased,and when the PVA fiber volume and nano-SiO_(2)dosage are both 2.0%,the lowest mass loss rate is 0.827%,and the highest corrosion resistance coefficient of the compressive strength is 0.995.