| 摘要: |
| 采用钢纤维和聚丙烯纤维对自密实轻骨料混凝土进行改性,完成了1组无纤维自密实轻骨料混凝土及4组钢聚丙烯混杂纤维自密实轻骨料混凝土的工作性能、力学性能及微观结构的试验研究,从宏观与微观2个尺度系统分析了钢聚丙烯混杂纤维的增强增韧机理.结果表明：5组自密实轻骨料混凝土均具有良好的流动性、黏聚性和间隙通过性,可满足自密实混凝土工作性要求;钢纤维与聚丙烯纤维可在不同结构层次和受荷阶段发挥阻裂作用,产生正协同效应,显著提高自密实轻骨料混凝土的劈裂抗拉强度和抗折强度;骨料基体界面区的密实度随养护龄期延长而明显提高,而纤维与基体间存在微细孔隙,界面区结构较为松散. |
| 关键词: 自密实轻骨料混凝土 工作性能 力学性能 微观结构 混杂纤维 |
| DOI：103969/j.issn.1007 9629202102006 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(52078042，51878054，51708036，51908041)；陕西省重点研发计划项目(2020GY 248) |
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| Properties of Self compacting Lightweight Concrete Reinforced with Hybrid Steel and Polypropylene Fibers |
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WU Tao, YANG Xue, LIU Xi
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School of Civil Engineering, Changan University, Xian 710061, China
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| Abstract: |
| Both steel fibers and polypropylene fibers were used to reinforce self compacting lightweight concrete(SCLC). One non fiber SCLC mixtures and four fiber reinforced SCLC mixtures were prepared to conduct the test of rheological properties, mechanical properties and microstructure of SCLC. The fiber reinforcement mechanism in SCLC was investigated on both macro and micro scales. The results show that all five mixtures satisfy the limitations of self compacting concrete that with good flowability, viscosity and passing ability. Steel and polypropylene fibers are effective in arresting cracks at different levels, generating a positive synergistic response, hence, splitting tensile and flexural strengths of SCLC are significantly improved. The microstructure of aggregate paste interface becomes denser with the increase in curing time. There are micro pores between fiber and matrix due to the existence of micro cracks and relatively loose structure. |
| Key words: self compacting lightweight concrete(SCLC) workability mechanical property microstructure hybrid fiber |
