Experimental and numerical investigation on projectile penetration resistance of prefabricated concrete targets

Prefabricated ultra-high-performance concrete (UHPC) target has the advantages of prominent anti-penetration capability and good construction quality. However, the interfaces in the prefabricated target would inevitably reduce its penetration resistance. To deal with this problem, a new prefabricated technique with the use of wet joints and rebars is proposed. To demonstrate the effectiveness of the proposed technique, two sets of projectile penetration tests on prefabricated targets assembled by prefabricated UHPC blocks, wet joints and rebars were firstly conducted and compared with corresponding experimental results of monolithic targets, demonstrating the comparable penetration resistance between prefabricated targets and corresponding monolithic targets. Then, based on the Kong-Fang model and SPG method, the numerical models of the two tests were developed and validated against the experimental data. The validated numerical models were further used to investigate the influences of interfaces, wet joints and rebars on the penetration resistance of prefabricated targets. The numerical results found that the horizontal interfaces have a limited influence on the penetration resistance while the vertical interfaces have a strong influence. It also numerically demonstrated the effectiveness of the proposed technique using wet joints and rebars to connect prefabricated blocks. The research results can provide an important reference for the use of prefabricated targets in protective engineering.