Ballistic perforation resistance of high performance concrete slabs with different unconfined compressive strengths

摘要

Ballistic penetration experiments have been carried out in a compressed gas gun using conical nosed steel projectiles and fibre reinforced high performance concrete slabs with nominal unconfined compressive strengths of 75 MPa, 150 MPa and 200 MPa. In all tests, nominal diameter, length, mass and hardness of the cylindrical projectiles were 20 mm, 98 mm, 0.2 kg and HRC 53, respectively, while the thickness and the free span diameter of the target plates were 100 mm and 500 mm, respectively. A total of 21 concrete slabs were tested. In each test, the initial projectile velocity was measured and the residual velocity was determined when possible. Furthermore, a digital high-speed camera system was used to photograph the penetration and perforation process. The ballistic limit velocity for each target material was precisely determined. It was found that even though the unconfined compressive strength of the concrete was increased by almost a factor of three, the increase in ballistic limit velocity (or capacity) was not more than about 20 %. Possible reasons for the experimental results will be discussed in view of the material behaviour of high strength concrete.