纤维混掺改性高强自密实混凝土试验与分析

Experiment and Analysis on the Modified HSCC Mixed with Composite Fibers

为研究不同结构层次纤维混掺对混凝土力学性能的改善作用,以镀铜微丝钢纤维和纳米碳纤维的掺量为参数,设计制备了纤维混掺改性高强自密实混凝土。试验表明:相较对照组,纤维改性混凝土的工作性能略有降低,而力学性能有不同幅度的提高,立方体抗压、轴压、劈裂、抗折强度的最大增幅分别为18.52%、21.10%、57.17%和54.40%。将数值分析与非线性回归结合,获得非样本纤维掺量下混凝土强度分析值的基础上,确定不同纤维的最优掺量。研究结果显示:适当掺量且分散良好的镀铜微丝钢纤维和纳米碳纤维混掺对高强自密实混凝土抗压、劈拉及抗折强度的提高分别存在超叠加、叠加及负混杂效应。

To study the effect of mixing composite fibers in different layers of structure on the mechanical property of concrete, the mixing amount of copper-coated steel fiber （SF） and carbon nanofiber （CNF） was used as parameter, and the modified HSCC mixed with composite fibers was designed and prepared. The experiment results indicate that compared with the control group, the modified concrete mixed with composite fiber has slightly lower working performance, while the mechanical properties are improved by differed degrees, with the maximum improvement of cube compressive, axial compression, splitting tensile and flexural strength reaching 18.52% , 21.10% , 57.17% and 54.40% respectively. Based on the analysis of the strength of non-sample concrete mixed with composite fiber, the optimal content of different fibers was determined by combining numerical analysis with non-linear regression. The study results show that the mix of well-distributed SF and CNF with appropriate amount has the superimposed, imposed and negative confounding effects on the improvement of compressive, splitting tensile and flexural strength of HSCC.