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A series of damage tests and axially repeated compressive tests with high strain rates were conducted to investigate the behavior of aramid fiber reinforced polymer (AFRP) wrapped concrete under repeated impacts. The relation between damage condition and variables such as impact number and polymer thickness were examined. The tests were performed using a 100 mm diameter Split Hopkinson Pressure Bar (SHPB) apparatus and a nonmetal supersonic test meter. Various AFRP layers were applied to produce varied confinement ratios. The experimental results indicated that the AFRP-wrapped concrete exhibited excellent performance in resisting repeated impacts. Also, the specimens maintained their shapes and bearing capacity after multiple impacts with a mean strain rate of 50 s−1. No distinct decline was observed from the history of peak stress and impact toughness in AFRP-wrapped concrete. Moreover, additional AFRP layers significantly decreased the impact damage on the core concrete, as reflected by the different strain rate histories in damage progression.

The dynamic mechanical properties of fiber-reinforced polymer (FRP) confined concrete were experimentally and theoretically studied using a 100-mm-diameter split Hopkinson pressure bar (SHPB) apparatus. As test results turned out, the dynamic strength of FRP-confined concrete was improved significantly. Within the mean strain rate range of 50–130 s−1, the dynamic strength increased with the rise in strain rate. With same strain rate, the strengthening effect was influenced by confining ratio. The optimal confining ratio of AFRP-confined concrete is 0.264, once beyond this limit, the failure pattern will be changed, and the dynamic strength will be decreased. In addition, a modified model was proposed for dynamic strength of FRP-confined concrete, which agrees with the test results well.

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