纳米SiO2和P VA纤维增强水泥基复合材料抗冻性能

摘要

为研究纳米SiO2和PVA纤维增强水泥基复合材料的抗冻性能,通过快冻法试验测得了各组试件经冻融循环后的相对动弹性模量,对单掺PVA纤维与复掺纳米粒子和PVA纤维水泥基复合材料的抗冻性能进行了对比,探讨了纳米SiO2与PVA纤维对水泥基复合材料抗冻性能的影响.结果表明:在一定掺量范围内掺加PVA纤维可以提高水泥基复合材料的抗冻性能,但过大掺量(>0.9%)的PVA纤维会对水泥基复合材料的抗冻性产生不利影响;在PVA纤维水泥基复合材料中掺入纳米SiO2可以明显提高其抗冻性能,在本文试验纳米SiO2掺量范围内,其抗冻性随着纳米SiO2掺量的增加不断增强;在掺加2%纳米SiO2的水泥基复合材料中掺加一定掺量(<0.9%)的PVA纤维可以提高水泥基复合材料的抗冻性.%The relative dynamic elastic modulus of specimens after freezing and thawing cycles were measured by freezing testing method to investigate the freezing resistance of the nano-SiO2 and PVA fiber reinforced cement matrix composites with the single addition of nano-SiO2 and combined addition of PVA fiber and nano-SiO2 particles. The influence of the content of nano-SiO2 and PVA fiber on the freezing resistance of cement-based composite materials was discussed. The results show that the content of PVA fiber in a certain range can improve the freezing resistance of cement-based composite materials, however too much content (> 0.9%) of PVA fiber has an adverse effect on the freezing resistance of cement-based composite materials. Adding nano-SiO2 into PVA fiber reinforced cement-based composite materials can significantly improve the freezing resistance. Within the range of the contents of nano-SiO2 in this study, with the increase of nano-SiO2 , the freezing resistance of cement-based composite materials is getting better and better. Adding 2% nano-SiO2 in cement-based composite materials mixed with a certain content (< 0.9%) of the PVA fibers can improve the freez-ing resistance of cement-based composite materials.