基于钢纤维与聚丙烯纤维的喷射混凝土弯曲韧性研究
Study on Flexural Toughness of Shotcrete Based on Steel Fiber and Polypropylene Fiber
许锋 1曾林 1柳德虎 1罗兰滨 1杨金光1
作者信息
- 1. 福建冶地恒元建设有限公司,福建福州 350108
- 折叠
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.
Abstract
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.
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Key words
shotcrete/bending toughness/steel fiber/polypropylene fiber/geometric dimensions/dosage引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据