超高性能混凝土轴心受拉力学性能试验研究

为了研究钢纤维掺量对超高性能混凝土(UHPC)轴心受拉力学性能的影响，设计、制作了纤维掺量为0%~5%的6组8字型单轴受拉试件，标准养护28 d后进行单轴拉伸试验，得到了不同纤维掺量UHPC单轴受拉应力-应变全曲线；分析了钢纤维掺量对UHPC抗拉强度、峰值应变以及受拉韧性的影响.试验结果表明：在不影响UHPC工作性能的前提下，纤维掺量可达到5%，其抗拉强度为8.50 MPa，对应的应变为1 619 με；随着钢纤维掺量的增加，UHPC的抗拉强度、峰值应变、抗压强度以及受拉韧性均逐渐提高.最后依据试验数据建立了UHPC单轴受拉本构方程.试验结果可为UHPC材料的工程应用提供参考.
In order to investigate the effect of fiber volume content on tensile characteristic of Ultra-High Performance Concrete (UHPC), 6 groups of “8” shape specimen were designed, and uniaxial tensile test was performed after 28 days standard curing, the complete tensile stress-strain curves were gotten, the effect of fiber volume content on tensile strength, peak strain and toughness of UHPC were analyzed. Test results show that the fiber volume content can be as much as 5% without workability problem, its tensile strength and peak strain are 8.50 MPa and 1 619 με respectively; with the fiber volume content increase the tensile strength, peak strain, compressive strength and toughness increase as well, the uniaxial tensile constitute of UHPC was finally proposed based on the test results. The results of this paper provide a reference for the application of UHPC material.