Resistance of double-layer reinforced HPC barriers to projectile impact

•We conducted impact experiments of double-layer HPC (DLHPC) specimens.•Effects of mix ingredients and thickness of front layer were studied.•Observations and analysis included perforation resistance and damage parameters.•We assess DLHPC thickness reduction based on fixed-thickness experimental results.

The resistance of double-layer reinforced high performance concrete (HPC) barriers to impact by a non-deforming projectile was studied experimentally. The methodology of this study consisted of comparative tests of various 800 × 800 × 200 mm3 reinforced concrete plate specimens that were subjected to impact by “reference projectiles” that were accelerated to different velocities using a gas gun system. The effects of aggregate size, use of steel fibers, and casting in layers were evaluated. Results include the perforation limit and performance under impact as determined from damage records of the different specimens. Analysis of the results also revealed the effects of mix ingredients of the front and rear layers on the barriers' performance. Specifically, it was found that steel fibers and appropriate use of large aggregates in different layers can enhance the overall impact resistance. Analysis of the results also included an assessment of the thickness reduction that can be obtained by applying these findings.