钢–聚丙烯混杂纤维混凝土力学性能研究
Study on Mechanical Properties of Steel-Polypropylene Hybrid Fiber Reinforced Concrete

为研究混杂钢-聚丙烯纤维对C60混凝土的力学特性和微观结构性能的影响，通过对掺入不同掺量和不同形状的纤维的试件进行力学试验，测得各组试件在不同阶段的抗压强度和抗折强度。钢纤维掺量分别为0%、0.5%、0.75%、1%、1.5%、0.25%，聚丙烯纤维掺量为0%、0.15%、0.25%，钢纤维种类有剪切型、铣削型、端勾型。结果表明随机分布的纤维可以发挥次筋作用，降低混凝土砂浆的流动性。掺入0.5%钢纤维和0.15%聚丙烯纤维的混凝土可以提高混凝土的抗压强度和抗折强度。粉煤灰取代率为20%时会降低混杂纤维混凝土的力学性能。剪切型钢纤维的掺入会使抗折强度下降，铣削、端勾型钢纤维可以同时提高混凝土的抗压强度和抗折强度，有利于提高混凝土延展性并且减少开裂。
In order to study the effect of blended steel-polypropylene fibers on the mechanical properties and microstructural properties of C60 concrete, the compressive and flexural strengths of each group of specimens at different stages were measured by conducting mechanical tests on specimens with different admixtures and different shapes of fibers. The dosage of steel fibers was 0%, 0.5%, 0.75%, 1%, 1.5%, and 0.25%, and the dosage of polypropylene fibers was 0%, 0.15%, and 0.25%, and the types of steel fibers were shear, milled, and end-hooked. The results show that the randomly distributed fibers can play the role of sub-reinforcement and reduce the fluidity of concrete mortar. Concrete with 0.5% steel fibers and 0.15% polypropylene fibers can increase the compressive strength and flexural strength of concrete. Fly ash substitution rate of 20% decreases the mechanical properties of mixed fiber concrete. The inclusion of shear type steel fibers will reduce the flexural strength, milling, and end-hooked type steel fibers can simultaneously increase the compressive strength and flexural strength of concrete, which is conducive to improving the ductility of concrete and reducing cracking.