摘要
使用聚丙烯纤维和钢纤维,分别以0.7%和1.0%体积掺量制备混凝土试件,设计不同纤维尺寸、形状的试验组,开展预切口三点弯曲试验,获取跨中挠度和混凝土弯曲荷载之间关系并计算弯曲韧性系数,对比掺入不同纤维条件下喷射混凝土的弯曲韧性提升差异。试验结果显示:所用纤维几何形状相同条件下,纤维长度和混凝土弯曲韧性之间保持正相关关系,但同时应考虑纤维长度因素会对混凝土工作性能产生的影响;纤维端部弯钩或表面压痕都能一定程度上提升纤维和基体之间的附着力水平。纤维几何尺寸相同条件下,掺入钢纤维的喷射混凝土增韧效果不及聚丙烯纤维,掺入1.0%聚丙烯纤维时的材料弯曲韧性指数I5达13.10。
Using polypropylene fibers and steel fibers,concrete specimens were prepared with a volume fraction of 0.7%and 1.0%,respectively.Test groups with different fiber sizes and shapes were designed to conduct pre-cut three-point bending tests.The relationship between mid span deflection and concrete bending load was obtained,and the bending toughness coefficient was calculated to compare the differences in bending toughness improvement of sprayed concrete under different fiber addition conditions.The experimental results show that under the same geometric shape of the fibers used,there is a positive correlation between fiber length and concrete bending toughness.However,the influence of fiber length on the workability of concrete should also be considered.Fiber end hooks or surface indentations can improve the adhesion level between the fibers and the matrix to a certain extent.Under the same geometric size of fibers,the toughening effect of sprayed concrete mixed with steel fibers is not as good as that of polypropylene fibers.When 1.0%polypropylene fibers are added,the material's bending toughness index(I5)reaches 13.10.
作者
许锋
曾林
柳德虎
罗兰滨
杨金光
XU Feng;ZENG Lin;LIU De-hu;LUO Lan-bin;YANG Jin-guang(Fujian Yedi Hengyuan Construction Co.,Ltd.,Fuzhou 350108,Fujian,China)
出处
《合成材料老化与应用》
CAS
2024年第1期78-80,共3页
Synthetic Materials Aging and Application
关键词
喷射混凝土
弯曲韧性
钢纤维
聚丙烯纤维
几何尺寸
掺量
shotcrete
bending toughness
steel fiber
polypropylene fiber
geometric dimensions
dosage
