Energy dissipation and fractal characteristics of basalt fiber reinforced concrete under impact loading

Basalt fiber reinforced concrete (BFRC) has been gradually used in buildings or structures to resist high-speed impact and explosion loading because of its good dynamic performance and energy absorption capacity. The dynamic compression experiments of BFRC with basalt fiber volume content of 0, 0.13 %, 0.26 % and 0.39 % were conducted using the Φ50 mm-diameter split Hopkinson pressure bar experimental system. The effects of different strain rates (80–220 s−1) on the dynamic compression property, dissipated energy (rate), fragmentation morphology and fractal dimension of BFRC were studied. Meanwhile, the SHPB impact numerical simulation of BFRC is carried out by LS-DYNA simulation platform. The results show that the peak stress and dissipated energy (rate) of BFRC increase with the increase of strain rate. However, the increase of the loading strain rate gradually decreases the fragmentation of BFRC, resulting in the continuous increase of the fractal dimension. The existence of basalt fiber as reinforcement in concrete increases the ability of concrete to resist impact cracking. BFRC with 0.26 % basalt fiber volume has higher dynamic compressive property and energy dissipation rate, but the fractal dimension of BFRC is the smallest compared with other contents. The stress–strain curves and damage evolution of BFRC under different loading rates are discussed by numerical simulation, which is further supplement to the experimental results.