Foamed, Fiber-Reinforced Concrete as a Fragment Collecting Medium

• Main Authors: Malone, Philip G, Tom, Joe G
• Format: Report
• Language: English
• Subjects: Ammunition and Explosives; AMMUNITION FRAGMENTS; DEBRIS; FIBER REINFORCEMENT; FIRING TESTS(ORDNANCE); FOAM; GRENADES; Guns; IMPACT POINT; Laminates and Composite Materials; LIFE EXPECTANCY(SERVICE LIFE); LIVE-FIRE TRAINING; PENETRATION; POLYPROPYLENE; RANGES(FACILITIES); REINFORCED CONCRETE; RICOCHET; SACON BLOCKS; SACON(SHOCK-ABSORBING CONCRETE); SMALL ARMS AMMUNITION; STEEL REINFORCED; SYMPOSIA

Foamed, fiber-reinforced concrete or shock-absorbing concrete (SACON) has been used successfully for years in structures designed for grenade and live-fire training exercises. The cellular structure of this type of concrete permits incoming bullets and fragments to bury themselves in the concrete without producing ricochets. Recent work on using foamed concrete in firing ranges has also shown that thick blocks of SACON can resist penetration from fragment impacts that occur at a single point beyond what might be predicted based on single projectile penetrations. Thick blocks of SACON when attacked with a weapon, such as the M16A2 rifle, firing multiple rounds into the same point develop pockets of dense bullet debris at the impact point that resist further penetration but do not produce ricochets. Low-density, steel fiber reinforced SACON blocks showed a reduced rate of penetration compared to polypropylene fiber-reinforced blocks of comparable density. Three-shot bursts of automatic fire produced penetration rates that were similar to those produced from three rounds fired as single shots. Dust produced from the blocks during shooting contains only minor amounts of metal from impacting bullets. The concentrated fire on a small arms range when directed at target area small enough to contain the debris in a compact mass may produce so little penetration that SACON can continue to be a useful, fragment-retaining barrier beyond the service life that would be predicted from the penetration depth observed for the initial shot. See also ADM001002. Published in the Proceedings of the DoD Explosives Safety Seminar (28th) held in Orlando, FL on 18-20 August 1998. The original document contains color images.