| 摘要: |
| 测试了混杂聚丙烯纤维（PPF）-回收轮胎钢纤维（RTSF）增强超高性能混凝土（UHPC）高温后的抗压强度，并研究了其工作性能.结果表明：PPF体积分数达到0.9%后，可以防止UHPC发生高温爆裂；UHPC的抗压强度随着温度的升高先增大后减小，400 ℃作用后达到最大值，比20 ℃作用后提高了9.2%~19.9%；相同温度作用后，UHPC的抗压强度随着PPF体积分数的增大而降低；PPF熔化前与基体有效黏结，其与RTSF均可发挥桥连作用，PPF熔化后在基体中形成孔道，提高了UHPC的耐高温性能. |
| 关键词: 超高性能混凝土 聚丙烯纤维 回收轮胎钢纤维 高温 力学性能 |
| DOI：10.3969/j.issn.1007-9629.2023.07.003 |
| 分类号:TU528.572 |
| 基金项目:国家自然科学基金资助项目（52178382）； 中央高校基本科研业务专项资金资助项目（N2201023）；辽宁省自然科学基金资助项目（2020-MS-089） |
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| Mechanical Properties of Hybrid Polypropylene Fiber-Recycled Tyre Steel Fiber Reinforced UHPC after Exposure to Elevated Temperatures |
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CHEN Meng1,2, LI Ao1, ZHANG Tong1
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1.School of Resources and Civil Engineering， Northeastern University， Shenyang 110819， China;2.Institute for Frontier Technologies of Low-Carbon Steelmaking， Northeastern University， Shenyang 110819， China
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| Abstract: |
| The workability and compressive strength of hybrid polypropylene fiber （PPF）-recycled tyre steel fiber （RTSF） ultra-high performance concrete （UHPC） were tested after exposure to elevated temperatures. The results show that the 0.9% volume fraction of PPF can prevent from spalling of UHPC during heating process. The compressive strength increases and then decreases with the increasing temperature， reaching its maximum value after being treated at 400 ℃， which is 9.2%-19.9% higher than that after being treated at 20 ℃. After the same temperature effect， the compressive strength of UHPC decreases with the increases of PPF volume fraction. PPF effectively adheres to the matrix before fiber melting， and can play a bridging role with RTSF. After fiber melting， PPF forms channels in the matrix， improving the high temperature resistance of UHPC. |
| Key words: ultra-high performance concrete polypropylene fiber recycled tyre steel fiber elevated temperature mechanical property |
