INTERIM REPORT ON USE OF STEEL FIBERS IN CONCRETE SLAB CONSTRUCTION TO RESIST SPALL CAUSED BY HIGH-EXPLOSIVE BLAST EFFECTS

摘要

In this report we discuss the use of steel fibers in reinforced concrete slab construction. These fibers help to reduce the spallation of concrete from the reverse side of slabs subjected to close-in, high-explosive detona¬tions. The effects of detonations of 20- and 49-lb charges of Composition 4 on seven 5-ft x 5-ft x 18-in.-thick reinforced concrete slabs are presented. Slabs were conventionally reinforced in both faces, with three slabs being ad¬ditionally fiber-reinforced. Distances from the charge center to face-of-slab ranged from 10 in. to 36 in. Z factors ranged from 0.28 to 1.0. Concrete fragment velocities ranged from 17 ft/s to 70 ft/s. The slabs constructed with steel fibers showed significantly less damage and spall than similar slabs without fibers.