
高温后玄武岩纤维混凝土冲击破碎分形特征
Fractal characteristics of fragments of basalt fiber reinforced concrete after elevated temperatures under impact loading
REN Wei-bo1,XU Jin-yu1,2,LIU Yuan-fei1,SU Hao-yang1
The dynamic fragmental characteristics of plain concrete (PC) and basalt fiber reinforced concrete (BFRC) after different temperatures, including fragments distribution, fractal dimension and energy dissipation capacities, were investigated by using a 100 mm diameter split Hopkinson pressure bar (SHPB) apparatus. The experimental results reveal that the fragments distribution of specimen statistically has fractal property under impact loading. The higher the temperature and projectile velocity, the severer the fragmentation and the larger the fractal dimension. Compared with PC, the fractal dimension of BFRC decreases at room temperature, 600 ℃ and 800 ℃, and decreases first and then increases with the increase of projectile velocity at 200 ℃ and 400 ℃. The addition of 0.2% (volume fraction) basalt fiber results in relatively higher fractal dimension. The energy dissipation density increases with the increase of fractal dimension under the same temperature, the fractal dimension corresponding to the same energy dissipation density increases with an increase in temperature. There are two critical points in the relationships between fractal dimension and projectile velocity, i.e., initiation projectile velocity and crushing projectile velocity. In this velocity range, the fractal evolution characteristics of fragmentation are obvious, the fractal dimension increases markedly. When the temperature increases, the critical projectile velocity decreases gradually.
玄武岩纤维混凝土 / 高温 / SHPB / 冲击破碎 / 分形维数 {{custom_keyword}} /
basalt fiber reinforced concrete / elevated temperature / SHPB / impact crushing / fractal dimension {{custom_keyword}} /
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