Systematic comparative tests on concrete wrapped with basalt fiber and carbon fiber reinforced polymer at moderately high strain rates

To compare the impact resistance of high-strength concrete wrapped with basalt fiber reinforced polymer and carbon fiber reinforced polymer, dynamic uniaxial compression tests were conducted on C50 concrete short column specimens at moderately high strain rates using a Φ100 mm split Hopkinson pressure bar apparatus. Based on the test phenomena and measured data, the dynamic stress-strain curves, energy absorption, and pattern of dynamic strength enhancement of the specimens with different wrapping layers were analyzed, and the differences in the confinement effects of the two fiber reinforced polymers were explained in terms of their action mechanisms. The results show that with the increase in the number of wrapping layers, both basalt fiber reinforced polymer and carbon fiber reinforced polymer can effectively enhance the dynamic strength, toughness and ductility of concrete. The difference is that the specimens wrapped with basalt fiber reinforced polymer exhibit superior ductility and impact toughness, with peak strains approximately 1.8 to 3.6 times those of the carbon fiber reinforced polymer wrapped specimens, whereas those wrapped with carbon fiber reinforced polymer achieve higher dynamic strength. A linear relationship is observed between the dynamic strength ratio and the confinement ratio for both types of specimens, and carbon fiber reinforced polymer has a higher confinement efficiency, approximately 2.6 times that of basalt fiber reinforced polymer, leading to a more significant enhancement in dynamic strength.