混合钢纤维活性粉末混凝土力学性能研究

Mechanical Properties of Hybrid Steel Fiber Reactive Powder Concrete

采用两种不同尺寸的钢纤维混合掺入活性粉末混凝土中;通过轴压、劈裂和四点弯曲的力学性能试验,研究混合钢纤维活性粉末混凝土的抗压强度、抗拉强度及抗折强度,得到不同钢纤维组合比例对活性粉末混凝土力学性能的改善作用;采用ASTMC1018提出的韧性指数法来衡量混合钢纤维活性粉末混凝土弯曲韧性。结果表明:同体积纤维掺量下,混合钢纤维活性粉末混凝土的立方体抗压强度、劈裂抗拉强度及弯曲抗折强度均较单掺一种纤维有一定程度的提高;混合掺入钢纤维后活性粉末混凝土韧性改善效果显著,采用0.5%长纤维与1.5%短纤维组合可以达到最佳增韧效果。

Two scales of steel fiber were mixed in the reactive powder concrete,and the compressive strength,tensile strength and flexural strength were studied by means of axial compression,splitting and four-point bending test to acquire the enhancement on the mechanical properties of reactive powder concrete with different ratio of steel fiber. The flexural toughness of hybrid steel fiber reactive powder concrete was measured by the toughness index method proposed by the ASTMC1018. The results show that the cubic compressive strength,splitting tensile strength and flexural strength of the hybrid steel fiber reactive powder concrete are improved to some extent compared with the single mixed fiber under the same mixed volume. The toughness improvement effect of reactive powder concrete is remarkable,and the best toughening effect can be achieved by using 0. 5% long fiber and 1. 5% short fiber.