钢-聚丙烯混杂纤维轻骨料混凝土弯曲韧性研究  

Flexural toughness of hybrid steel-polypropylene hybrid fiber reinforced lightweight aggregate concrete

作　　者：刘胜兵 郑宇航 梅浩华 张永磊 张璐 LIU Shengbing;ZHENG Yuhang;MEI Haohua;ZHANG Yonglei;ZHANG Lu(School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China)

机构地区：[1]武汉工程大学土木工程与建筑学院,湖北武汉430074

出　　处：《武汉大学学报(工学版)》2025年第3期379-387,共9页Engineering Journal of Wuhan University

基　　金：国家自然科学基金项目(编号:51878518);湖北省教育厅科学研究计划项目(编号:B2015313)。

摘　　要：采用正交试验法研究了钢纤维体积掺量、聚丙烯纤维长径比及体积掺量对轻骨料混凝土弯曲初裂强度、极限抗弯强度和弯曲韧性指数的影响,基于试验数据建立了混杂纤维轻骨料混凝土抗弯强度预测模型。借助层次分析法综合分析了各影响因素对试验指标的综合影响权重,筛选出增强、增韧效果最佳的纤维掺量组合。结果表明:钢纤维掺量对轻骨料混凝土弯曲性能的影响较大,随着钢纤维掺量的增加,轻骨料混凝土的抗弯强度、弯曲韧性相应提高;聚丙烯纤维对抗弯强度的影响较弱,随着聚丙烯纤维掺量和长径比的增大,试件的抗弯强度略有提升,且聚丙烯纤维体积掺量不宜超过0.09%;在弯曲破坏前期,聚丙烯纤维对弯曲韧性指数的影响要优于钢纤维,钢纤维的影响权重随着跨中挠度持续增加而逐渐提高。综合分析多项试验指标后建议最佳纤维掺量配比为:钢纤维体积率1.5%、聚丙烯纤维长径比392、体积率0.09%。The influences of steel fiber volume content,polypropylene fiber length-diameter ratio and volume content on flexural initial crack strength,ultimate flexural strength and flexural toughness index of lightweight aggregate concrete were studied by orthogonal test method.Based on the experimental data,the flexural strength prediction model of hybrid fiber lightweight aggregate concrete was established.With the help of analytic hierarchy process(AHP),the comprehensive influence weight of each influencing factor on the test index was comprehensively analyzed,and the fiber content combination with the best reinforcement and toughening effect was screened out.The results show that the content of steel fiber has a great influence on the flexural properties of lightweight aggregate concrete.With the increase of the content of steel fiber,the flexural strength and flexural toughness of lightweight aggregate concrete increase accordingly.The effect of polypropylene fiber on the bending strength is weak.With the increase of the polypropylene fiber content and the length to diameter ratio,the bending strength of the specimen is slightly improved,and the volume content of polypropylene fiber should not exceed 0.09%.In the early stage of bending failure,the influence of polypropylene fiber on the bending toughness index is better than that of steel fiber.With the continuous increase of mid-span deflection,the influence weight of steel fiber gradually increases.Based on comprehensive analysis of several test indexes,it is suggested that the optimum steel fiber volume content is 1.5%,the polypropylene fiber aspect ratio is 392,and the volume fraction is 0.09%.

关 键 词：弯曲韧性指数 强度预测模型 层次分析法 混杂纤维 正交试验 

分 类 号：TU528[建筑科学—建筑技术科学]