多尺度聚丙烯纤维混凝土单轴拉伸试验

Uniaxial tensile test of multi-scale polypropylene fiber reinforced concrete

采用环氧粘贴法对21个100mm×100mm×250mm混凝土和聚丙烯纤维混凝土试块进行单轴抗拉试验,研究不同尺度聚丙烯纤维及其混杂对混凝土单轴抗拉性能的影响,分析不同尺度聚丙烯纤维混凝土的单轴拉伸应力应变全曲线。试验结果表明:单掺及混掺粗细聚丙烯纤维对混凝土抗拉强提高幅度为11%～27%;单掺粗聚丙烯纤维混凝土及粗细混掺聚丙烯纤维混凝土在单轴拉伸过程中出现了低应力应变硬化现象,单掺及混掺粗细聚丙烯纤维混凝土应力应变曲线下降段所包围面积大于素混凝土应力应变曲线下包面积。不同尺度聚丙烯纤维混凝土抗拉韧性增强效果排序:混掺粗细纤维混凝土>单掺粗纤维混凝土>单掺细纤维混凝土>素混凝土。

Based on uniaxial tensile test on 21 plain and polypropylene fiber concrete specimens with the dimensions of 100 mm × 100 mm × 250 mm with epoxy paste method,the influence of the different scales of polypropylene fiber and hybrid fiber on concrete uniaxial tensile strength is investigated,and the uniaxial tensile stress-strain whole curves of the different scale polypropylene fiber reinforced concrete is analyzed.Single-doped and blended polypropylene fiber can improve the tensile strength of concrete by 11% to 27%、 The strain hardening of low-stress occurs during the uniaxial tensile for the single-doped crude polypropylene fiber and blended polypropylene fiber concrete,and the surrounding area of the descent stage of single-doped and blended polypropylene fiber concrete stress-strain curves is larger than the plain concrete stress-strain curve of the package area.The tensile toughness enhancement effect of different scales of polypropylene fiber concrete is illustrated as blended fiber concrete〉 single-doped coarse fiber concrete 〉 single-doped fine fiber concrete〉 plain concrete.