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为了研究钢纤维混凝土(SFRC)常温以及经历400和800℃高温后的动态压缩性能,采用改进的分离式Hopkinson压杆装置,结合应变直测技术对其进行了单轴冲击压缩试验.结果表明:经历400和800℃高温后,未掺钢纤维混凝土的峰值应力分别只有常温时的79.2%和38.9%,弹性模量分别降为常温时的82.8%和56.2%,同时,试件的能量吸收能力大幅度下降;钢纤维混凝土400,800℃对应的峰值应力分别降为常温时的76.8%和39.0%,弹性模量稍有降低,分别为常温的91.8%和82.7%,较基准混凝土有了较大的提高.钢纤维的加入可以增加混凝土的极限应力对应应变,曲线的下降段较为平缓,同时增强了混凝土的能量吸收能力,在20,400和800℃时,分别提高了38.5%,27.5%和25%.
In order to study the dynamic compressibility of steel fiber reinforced concrete (SFRC) at normal temperature and high temperature of 400 and 800 ℃, a uniaxial impact compression test was carried out by using the improved split Hopkinson pressure bar device in combination with strain direct measurement technology. The results show that: After 400 and 800 ℃ high temperature, the peak stresses of un-doped steel fiber reinforced concrete were only 79.2% and 38.9% respectively at room temperature, and their elastic moduli were reduced to 82.8% and 56.2% respectively at normal temperature. At the same time, the energy absorption capacity The peak stresses at 400 and 800 ℃ of steel fiber reinforced concrete decreased to 76.8% and 39.0% respectively at room temperature and the elastic modulus decreased slightly, which were 91.8% and 82.7% at room temperature respectively, which were larger than that of the benchmark concrete The steel fiber can increase the ultimate stress corresponding strain of concrete, the curve of the descending section is more gentle, and enhance the energy absorption capacity of concrete at 20,400 and 800 ℃, respectively, increased 38.5%, 27.5% and 25%.