纳米SiO_(2)和PVA纤维增强水泥基复合材料的断裂性能  

Fracture Properties of Nano-SiO_(2) and PVA Fiber Reinforced Cementitious Composites

作　　者：张鹏[1] 亢洛宜 郭进军[1] 王娟[1] ZHANG Peng;KANG Luoyi;GUO Jinjun;WANG Juan(School of Water Conservancy Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学水利科学与工程学院,河南郑州450001

出　　处：《建筑材料学报》2021年第5期908-915,共8页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51678534);河南省高校科技创新团队支持计划(20IRTSTHN009)。

摘　　要：通过18组共90根纳米SiO_(2)和聚乙烯醇(PVA)纤维增强水泥基复合材料预制切口小梁试件的三点弯曲断裂试验,以起裂断裂韧度和断裂能作为评价指标,探讨了纳米SiO_(2)掺量、PVA纤维体积分数及石英砂粒径对水泥基复合材料断裂性能的影响.结果表明:适量的纳米SiO_(2)和PVA纤维可显著改善试件的断裂性能,在未掺纳米SiO_(2)或纳米SiO_(2)掺量为2.0%条件下,随着PVA纤维体积分数的增加,试件的起裂断裂韧度和断裂能均呈现先增后减趋势,且均在PVA纤维体积分数为1.2%时达到最大值.当纳米SiO_(2)掺量小于1.5%时,试件的断裂性能随着纳米SiO_(2)掺量的增加而提高;当纳米SiO_(2)掺量大于1.5%时,纳米SiO_(2)的掺入对试件的断裂性能有不利影响;随着石英砂粒径的减小,试件的断裂性能逐渐降低.Through three-point bending fracture test of 18 groups of 90 pre-cut beam specimens of cementitious composite,the effect of polyvinyl alcohol(PVA)fiber and nano-SiO_(2)contents on fracture properties of cementitious composite was revealed on condition that PVA fiber and nano-SiO_(2)was added alone and by blending.The initial fracture toughness and fracture energy were used to evaluate fracture properties of cementitious composite.The results show that a moderate amount of PVA fiber and nano-SiO_(2)incorporation can improve fracture properties of cementitious composite significantly.The initial fracture toughness and fracture energy of the beam specimens of cementitious composite without nano-SiO_(2)and cementitious composite containing 2.0%nano-SiO_(2)increase first and then decrease with the increase of PVA fiber volume content,and all the fracture parameters reach the maximum in the volume fraction of 1.2%of PVA fiber.When the content of nano-SiO_(2)is less than 1.5%,the fracture properties of PVA fiber reinforced cementitious composite improve gradually with the increase of nano-SiO_(2)content,however,the fracture properties of PVA fiber reinforced cementitious composite are adversely affected when the content of nano-SiO_(2)exceeds 1.5%.With the decrease of quartz sand particle size,the fracture properties of nano-SiO_(2)and PVA fiber reinforced cementitious composite decrease gradually.

关 键 词：水泥基复合材料 PVA纤维 纳米SiO_(2) 起裂断裂韧度 断裂能 

分 类 号：TU528.0[建筑科学—建筑技术科学]