高延性水泥基复合材料用短切PVA纤维的长度优选研究  

Study on PVA Fiber Length Optimization for High Ductility Cementitious Composites

作　　者：丁聪 任金明 王永明 李新宇 俞兵 郭丽萍[2] DING Cong;REN Jinming;WANG Yongming;LI Xinyu;YU Bing;GUO Liping(POWERCHINA Huadong Engineering Corporation Limited,Hangzhou 310000,China;School of Materials Science and Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]中国电建集团华东勘测设计研究院有限公司,杭州310000 [2]东南大学材料科学与工程学院,南京211189

出　　处：《材料导报》2023年第13期249-256,共8页Materials Reports

基　　金：浙江省自然科学基金(LTGS23E090002);国家自然科学基金(51778133);华东勘测设计研究院有限公司201科技项目(KY2021-ZD-01)。

摘　　要：为优选高延性水泥基复合材料(HDCC)用短切聚乙烯醇(PVA)纤维的长度,采用6 mm、9 mm、12 mm、18 mm和24 mm五种长度的PVA纤维,在体积掺量为1.0%的情况下制备HDCC,研究PVA纤维长度对HDCC工作性能、力学性能和纤维桥联能力的影响。结果表明:随着纤维长度的增加,HDCC新拌浆体流动性逐渐降低,当纤维长度从6 mm增加到9 mm时浆体流动性显著下降39%;纤维的掺入提升了HDCC的抗压、抗折强度,但其增幅与纤维长度相关性不大;掺入18 mm纤维制备的HDCC展现出最高的弯曲强度,而掺入9 mm纤维制备的HDCC展现出最高的跨中挠度和弯曲耗能;随着纤维长度的增加,纤维桥联应力和桥联余能均增大,但由于纤维断裂效应越显著,纤维桥联应力和桥联余能增幅逐渐变缓。基于HDCC工作性能、力学性能以及纤维桥联能力的试验与计算结果,9 mm长度的PVA纤维是较为合适的选择。In order to optimize the PVA fiber length for high ductility cementitious composites(HDCC),the PVA fibers with 6 mm,9 mm,12 mm,18 mm and 24 mm were adopted in this study,then the effects of PVA fiber length on the workability,mechanical properties and bridging abilities of HDCC were investigated.Results showed that the fluidity of fresh HDCC decreased gradually with the increase of fiber length,and the fluidity significantly decreases 39%when the fiber length increases from 6 mm to 9 mm.The compressive strength and flexural strength of HDCC increase with the addition of fiber,but it has little correlation with the fiber length.HDCC with 18 mm fibers showed the highest bending strength,while HDCC with 9 mm fibers showed the highest mid-span deflection and bending energy consumption.Micromechanical analysis shows that with the increase of fiber length,the fiber bridging abilities are stronger,the increase of fiber bridging stress and complementary energy gradually slows down due to seriously ruptured effect of fibers.Based on the test and calculation results of HDCC working properties,mechanical properties and fiber bridging capacity,the more appropriate choice of 9 mm fibers is obtained.

关 键 词：高延性水泥基复合材料(HDCC) 纤维长度 工作性能 力学性能 桥联能力 

分 类 号：TU528[建筑科学—建筑技术科学]