| 摘要: |
| 对120个经20~900℃作用后、尺寸为70.7mm×70.7mm×228.0mm的混杂纤维活性粉末混凝土(RPC)试件进行了单轴受压试验，分析了纤维掺量和经历温度对混杂纤维RPC轴心抗压强度、弹性模量、峰值应变和受压应力应变曲线的影响.结果表明：相同高温作用后，钢纤维掺量为1%（体积分数）的混杂纤维RPC抗压强度最低，而钢纤维掺量为2%，聚丙烯纤维掺量不同的混杂纤维RPC抗压强度差别不大；轴心抗压强度和弹性模量随经历温度的升高先增大后减小，且弹性模量下降速度比抗压强度快；经历温度为600℃时，峰值应变达到最大值，且峰值点前应变迅速增大，峰值点后呈线性减小.通过回归分析，建立了抗压强度、弹性模量和峰值应变随温度变化的计算公式，提出了用五次多项式和有理分式表达的混杂纤维RPC应力应变曲线方程.与普通混凝土和高强混凝土相比，混杂纤维RPC具有更优越的抗高温性能. |
| 关键词: 活性粉末混凝土(RPC) 高温 力学性能 应力应变关系 |
| DOI：10.3969/j.issn.1007 9629.2013.03.003 |
| 分类号: |
| 基金项目:土木工程防灾国家重点实验室基金资助项目（SLDRCE09 D 02） |
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| Compressive Stress Strain Relationship of Hybrid Fiber Reinforced ReactivePowder Concrete after Exposure to High Temperature |
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ZHENG Wen zhong, LI Hai yan, WANG Ying
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School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China
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| Abstract: |
| The uniaxial compression experiments were conducted on 120 specimens with the size of 70.7mm×70.7mm×228.0mm for hybrid fiber reinforced reactive powder concrete(RPC) after being exposed to 20900℃. The effects of fiber content and exposure temperature on the mechanical properties of RPC were investigated, including the uniaxial compressive strength, elastic modulus, peak strain, and compressive stress strain curves. The results show that: For the same heating treatment, the compressive strength of RPC with steel fiber volume use level of 1% is the lowest, while the compressive strength of RPC with steel fiber volume use level of 2% and different polypropylene fiber volume use level are almost the same; The uniaxial compressive strength and elastic modulus increase first and then decrease with increasing temperature, and the elastic modulus lowers faster than the compressive strength; and the peak strain reaches the maximum at 600℃, and it increases rapidly before the peak points but decreases linearly with temperature after the peak points. Through regression analysis, the equations to express the relationship of the compressive strength, elastic modulus and peak strain with the maximum exposure temperature are proposed to fit the test results. Besides, quintic polynomial and rational fraction are used to fit the stress strain curves of RPC. The hybrid fiber reinforced RPC has excellent capacity in resistance to high temperature compared with natural strength and high strength concrete. |
| Key words: reactive powder concrete(RPC) high temperature mechanical property stress strain relationship |
