中文摘要：

通过纤维纳米混凝土棱柱体试件在25～800℃高温中的单轴受压试验，研究了温度、钢纤维体积率、纳米二氧化硅和纳米碳酸钙掺量对纤维纳米混凝土高温中轴压性能的影响。结果表明，随温度升高，纤维纳米混凝土峰值应力和初始弹性模量显著降低，峰值应变明显增大；随钢纤维体积率增大，高温中纤维纳米混凝土峰值应力和峰值应变不断提高，初始弹性模量有所下降；随纳米材料掺量增加，高温中纤维纳米混凝土峰值应力、峰值应变和仞始弹性模量均呈增大的趋势，纳米二氧化硅的效果好于纳米碳酸钙。在分析试验结果的基础上，提出了考虑温度、纤维和纳米材料影响的高温中纤维纳米混凝土峰值应力、峰值应变和初始弹性模量的计算公式以及高温中纤维纳米混凝土单轴受压应力-应变关系式。

英文摘要：

Through the uniaxial compression tests on prism specimens in different temperatures which range from 25 to 800℃, the effects of temperature, steel fiber volume fraction, Nano-SiO2 and Nano-CaCO3 content on uniaxial compressive behavior of fiber and nanosized materials reinforced concrete （FNMRC） were investigated. The experimental results indicate that the peak stress, peak strain and initial elastic modulus of FNMRC decreased significantly with the temperature. The peak stress and peak strain of FNMRC in high temperature increase with the steel fiber volume fraction, while the initial elastic modulus decrease. With the increase of nanosized materials content, the peak stress, peak strain and initial elastic modulus of FNMRC in high temperature show a trend of increase. The influence of Nano- SiO2 on the compressive behavior of FNMRC is better than the Nano-CaCO3. Based on the test results, the stress-strain constitutive relationship and calculation methods of peak stress, peak strain and initial elastic modulus of FNMRC in high temperature are proposed, in which the effects of temperature, steel fiber volume fraction and nanosized materials content are taken into account.