【摘要】 通过51个钢-聚丙烯混杂纤维混凝土试件的中心拉拔试验,研究钢-聚丙烯混杂纤维混凝土与变形钢筋的黏结性能,分析钢纤维体积率、钢纤维长径比、聚丙烯纤维体积率和混凝土强度对黏结性能的影响,建立黏结本构关系。结果表明:对极限黏结强度的影响排序为,混凝土强度最大,钢纤维的体积率和长径比次之,聚丙烯纤维体积率最小;随着钢纤维体积率、钢纤维长径比和混凝土强度的增大,极限黏结强度分别提高18.4%、17.4%和50.5%,峰值滑移分别提高39%、38%和31%,聚丙烯纤维体积率的变化对极限黏结强度和峰值滑移没有明显影响;与钢纤维混凝土、聚丙烯纤维混凝土和普通混凝土相比,极限黏结强度相应提高5.3%、21.3%和18.2%,峰值滑移相应提高2.8%、36%和90%。提出黏结应力-滑移全曲线的数学表达式,可为钢-聚丙烯混杂纤维混凝土的工程应用和《纤维混凝土结构技术规程》的修订提供参考。更多还原

【Abstract】 In order to study the bond properties and bond constitutive relationship between hybrid fiber reinforced concrete( HFRC) and deformed bar,the effects of aspect ratio of steel fiber,strength of concrete,steel fiber and polypropylene fiber volume fraction were analyzed through the pull-out experiments on 51 specimens with hybrid steelpolypropylene fibers. Results of orthogonal experiment showed that the strength of concrete played the most important role in improving the ultimate bond stress,whereas the polypropylene fiber volume fraction had the minimum effect. The ultimate bond stress was increased by 18. 4%,17. 4% and 50. 5% while the corresponding slip was increased by 39%,38% and 31% as steel fiber volume fraction,aspect ratio of steel fiber and strength of concrete were increased in HFRC. However,the ultimate bond stress and the corresponding slip were nearly the same with polypropylene fiber volume fraction changed in HFRC. When compared to steel fiber reinforced concrete,polypropylene fiber reinforced concrete and normal concrete,the ultimate bond stress in HFRC was increased by 5. 3%,21. 3% and 18. 2% while the corresponding slip was increased by 2. 8%,36% and 90%. From the experimental bond stress and slip curve,the expression of the bond constitution relationship was presented. The fitting results could provide a reference to engineering application and further refining of technical specifications for fiber reinforced concrete structures.更多还原