关键词: 混掺纤维;高强自密实混凝土;力学性能;数值分析

Abstract: 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.

Key words: composite fiber;high-strength self-compacting concrete;mechanical property;numerical analysis