温度、应变率对碳纤维混凝土变形特性的影响

Effects of temperature and strain rate on the deformation property of carbon fiber reinforced concrete

采用自主研制的高温SHPB试验系统,对高温条件下碳纤维混凝土(CFRC)的变形特性进行了试验研究。结果表明:高温下CFRC的动态峰值应变同时存在加载速率强化效应和温度弱化效应。动态极限应变存在加载速率强化效应;同一加载速率下随温度的升高先降低后增大的变化趋势,200℃以前,以温度弱化效应为主,200℃以后,以温度强化效应为主;800℃时的动态极限应变要高于常温时的情况。碳纤维可以有效提高混凝土在不同温度和加载速率下的动态变形能力,当碳纤维体掺量为0.3%时,增幅最大,其次是0.1%CFRC和0.2%CFRC。

The deformation property of carbon fiber reinforced concrete （CFRC） at elevated temperature is investigated using selfdesigned high temperature SHPB system.The results showed load rate strengthening effect and temperature weakening effect on the dynamic critical strain of CFRC.Dynamic limit increased with load rate.At the same load rate, the dynamic limit strain increased before 200 ℃ and decreased after 200 ℃ .At 800 ℃ ,it was higher than that at room temperature.Carbon fiber could effectively enhance the dynamic deformation property of concrete at different temperature and load rate.The increase ratio reached the maximum at the volume fraction of 0.3%.Then follow 0.1% and 0.2%.