HIGH-STRENGTH CONCRETE RESPONSE TO HARD PROJECTILE IMPACT

High strength concrete (HSC) becomes more common in practice and may h ave advantageous implementations. According to existing penetration fo rmulae HSC is expected to enhance the performance of structural elemen ts that are designed to resist projectile impacts. However, scabbing a t the rear face is expected to be more severe in elements that are mad e of HSC, because of the relatively high material brittleness. Therefo re, it is important to enhance the ductility of HSC elements, and one possible direction is to use fibers or wire mesh reinforcement. In ord er to study the influence of the concrete strength and of the reinforc ement type on the elements response, penetration tests were conducted on regular strength concrete (RSC) and on HSC plates, with the followi ng types of reinforcement: 5 mm steel mesh, steel fibers, small diamet er steel wire mesh, and woven steel fence mesh of various diameters. T he plates were subjected to an impact of a cylindrical hard steel proj ectile, weighing 120 g, with a conical nose and a 1.5 aspect ratio. Th e projectiles were accelerated by a Laboratory gas gun to velocities t hat ranged between 85 and 230 m/sec, which were measured by an electro -optical device. By comparing the response of these plates to an impac ting projectile, the effects of concrete strength and of the reinforce ment were studied. Major trends of the elements behavior were studied, their responses were compared and are described herein. Copyright (C) 1996 Elsevier Science Ltd.