Influence of acrylic fibre content of concrete on local impact damage

Abstract

To address crater formations in concrete structures caused by the impact of fragments, thus investigate the possibility of improving the overall capacity upon such occurrences. The objectives of this study are to assess the effect of reinforcing acrylic fibres into concrete, as well as varying percentages in content, with the aim of improving the concrete’s energy absorption ability against dynamic impact and study other physical and mechanical properties between the plain concrete and acrylic fibre reinforced concrete. In total, thirty-six concrete specimens were cast, of which twenty-seven cubes were subjected to high-velocity dynamic impact using the Projectile Gas Gun Test. Stainless-steel type 316 projectile of 12mm in diameter was launched at striking velocities ranging from 118.9 m/s to 168.1m/s, and the damage of the concrete targets were assessed. Along with the remaining nine cylindrical concrete specimens which were subjected to static compressive strength test using a universal compressive test machine to assess the compressive strength and elastic modulus. The capability of Acrylic Fibre Reinforced Concrete in providing resistance against high-velocity impact damage was assessed by measuring the crater depth, area and volume. Influences of percentage of acrylic fibre content at varying velocities of the projectile on the impact crater depth, area and volume of the concrete specimens were discussed. Results from the static test indicate that the mechanical properties such as the compressive strength of the acrylic fibre reinforced concrete was significantly reduced as compared to the plain concrete. As for the dynamic impact test on the concrete specimens, despite not a significant difference, results showed that the higher content of 0.4% acrylic fibres in concrete displayed slight improvement in crater size as compared to a lower percentage of acrylic fibre reinforced concrete and plain concrete, at varying velocities. Hence, indicates a stronger resistance to impact [1]. However, the addition of acrylic fibres content of 0.2% exhibited more consistent results due to the better outcome of the concrete specimens during the mixing process. Furthermore, the addition of acrylic fibres in concrete proved to be able to increase the energy absorption and avoid micro-cracks from propagating, thus ultimately improving the performance of the concrete specimens.