高强混合钢纤维混凝土的力学性能

Mechanical Properties of Hybrid Steel Fiber Reinforced High Strength Concrete

为改善高强混凝土的脆性,将2种尺寸的钢纤维混合掺入高强混凝土中,通过抗压强度、抗拉强度及抗折强度分析了不同钢纤维混掺对其力学性能的改善作用;采用ASTM C1018方法分析了高强混合钢纤维混凝土的韧性.结果表明:长、短钢纤维混掺会降低高强混凝土的流动性,且短钢纤维对其流动性影响更为显著;在相同掺量(体积分数)下,混掺钢纤维高强混凝土的抗压强度及抗折强度较单掺钢纤维高强混凝土高;当长、短钢纤维混掺比适当时,其劈裂抗拉强度也有所提高;长、短钢纤维混掺对高强混凝土韧性改善效果显著,采用1.50%长钢纤维与0.50%短钢纤维混掺可达到最佳增韧效果.

To reduce the brittleness of high strength concrete, two steel fibers with different geometrical size were added into the high strength concrete matrix. The compressive strength, tensile strength and flexural strength were tested to obtain the empirical function of the high strength concrete with different fiber combinations. Meanwhile, ASTM C1018 standard was used to measure the flexural toughness of the hybrid steel fiber reinforced high strength concrete. The test results show that the fluidity will drop when long steel fibers and short steel fibers are added. The influence of short steel fibers on the fluidity is signif- icant. The hybrid fiber reinforced high strength concrete are superior to only the long fibers reinforced one in the cubic compressive strength and flexural strength under the same volume contents. The splitting and tensile strength are enhanced when suitable combination is used. Flexural toughness of the high strength concrete is most improved by adding hybrid steel fiber with 1. 50% long steel fibers＋0.50% short steel fibers.