中文摘要：

采用自行设计的耐高温装具及卡具，对普通混凝土（NC）、钢纤维混凝土（SFRC）和掺入纳米SiO2钢纤维混凝土（NSFC）3种材料，分别在高温电炉中加热到不同温度，进行高温时轴向拉伸试验。结果表明：400℃以内时，NSFC、SFRC和NC的轴向拉伸随温度升高而升高，400℃时达到最大值，此后，随温度升高，轴向拉伸强度迅速下降。掺纳米SiO2的钢纤维混凝土NSFC轴向拉仲强度最大，常温下为2．66MPa，足普通混凝土NC的4．29倍，比未掺纳米SiO2的钢纤维混凝土SFRC还高52．9％。400℃时为3．09MPa，较400℃下的SFRC提高9．2％、较NC提高119．7％。

英文摘要：

The independently-designed heat-resistant temperature harness and fixtures were used in the axial tension experiment at high temperature.Three materials were tested in the experiment, including normal concrete（ NC ）, steel fiber reinforced concrete （SFRC） and steel fiber reinforced concrete with nano SiO2 （NSFC）, which were heated to different temperatures in the high-temperature electric resis- tance furnace.Results presented that within 400 ℃, the axial tensile strength of NSFC, SFRC and NC were improved as temperature in- creased, reaching a maximum value at 400 ℃ .After that, the temperature rise led to rapid drop of the axial tensile strength.At room temper- atures,the axial tensile strength of NSFC was the largest,as 2.66 MPa,which was 4.29 times than NC,and 52.9% higher than SFRC.At 400 ~C, the axial tensile strength of NSFC was 3.09 MPa, 9.2% higher than SFRC and 119.7% higher than NC.