Estudo do desempenho de blocos de concreto balístico reforçados com fibra de aramida para aplicações em segurança: identificação de danos em escala global e local

Abstract

The growing need for security in society, driven by numerous armed conflicts, whether in warlike or urban settings, emphasizes the imperative demand to safeguard citizens, equipment, facilities and infrastructure. This research emerged from the pressing need of the Military Police of the State of Rio de Janeiro to build buildings in areas affected by drug trafficking and considered as risk zones. The scope of this investigation focuses on the study of concrete with aramid blanket subjected to ballistic impact, aiming to optimize the performance of concrete structures subject to such impacts. Two models of concrete blocks were made, both enriched with the addition of six layers of aramid blanket, located approximately 5 cm from the surface subject to attack. All specimens were subjected to ballistic impacts, with one 5.56 mm shot and three 7.62 mm shots being analyzed for global and local damage, depth of penetration of the projectile and loss of mass. It was evident that the internal incorporation of the aramid blanket contributed to the propagation of cracks and resulted in a mass loss of around 2.2%, pointing to insufficient adhesion between the concrete and the blanket. Such findings highlight the relevance of continuing with investigations aimed at improving resistance and protection in concrete structures exposed to ballistic impacts.