混杂纤维喷射混凝土弯曲韧性圆板法试验研究*
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（湖北工业大学土木工程与建筑学院， 武汉 430068）
［摘要］选用超短微丝钢纤维、多锚点钢纤维分别与聚丙烯纤维混杂的喷射混凝土进行立方体抗压、圆板法弯曲韧性试验。通过荷载挠度曲线与混凝土板的能量吸收值，研究了纤维掺量、纤维类型以及聚丙烯纤维对混杂纤维喷射混凝土弯曲韧性与变形性能的影响。研究结果表明：喷射混凝土板的弯曲韧性和抗弯承载力随着钢纤维掺量的增加而增加；超短微丝钢纤维喷射混凝土的抗弯韧性与裂缝控制能力均优于多锚点钢纤维喷射混凝土；当体积掺量为1.2%的超短微丝钢纤维与体积掺量为0.11%的聚丙烯纤维混杂时的喷射混凝土表现出的弯曲性能和抗压强度最优。［关键词］混杂纤维; 喷射混凝土; 弯曲韧性; 圆板法; 能量吸收值中图分类号：TU528.572 文献标识码：A 文章编号：1002-848X(2015)12-0018-05
Round panel test study on flexural toughness of hybrid fiber shotcretingXia Dongtao, Zhang Yanfang, Zhang Zhouqiang, Zhu Yuting(Civil Engineering and Building Academy, Hubei University of Technology, Wuhan 430068, China)Abstract: The compressive strength and round panel flexural toughness test were carried out on mixing of polypropylene hybrid fibers and shotcreting with two kinds of ultrashort microfilament steel fibers and multiple anchor steel fibers respectively. Based on the loaddeflection curve and energy absorption value for the concrete slab, the effects of steel fiber volume fraction, steel fiber type and the addition of the polypropylene fibers on flexural toughness and deflection performance for hybrid fiber shotcreting were investigated. The results show that the flexural strength and flexural toughness of shotcreting slab increase with the increase of steel fiber volume fraction. The flexural toughness and crack control ability of ultrashort microfilament steel fibers shotcreting exceed that of multiple anchor steel fiber shotcreting. The hybrid fiber shotcreting with 1.2% of ultrashort microfilament steel fibers and 0.11% of the polypropylene fibers show the best flexural toughness and highest compressive strength.Keywords: hybrid fiber; shotcreting; flexural toughness; round panel test; energy absorption value
*国家自然科学基金青年项目(51108164)。作者简介：夏冬桃，博士，副教授，Email:xdtxy@126.com。
