Resistance of Fiber Reinforced Concrete Plates to Dynamic Loads

Abstract

The objective of this work is to study the effect of impact and blast dynamic loading upon concrete plates reinforced with normal deformed steel bars as well as steel or glass fibers. In order to examine the effect of using different volume and weight fractions of s skeletal bars and steel or glass fiber reinforcements on the impact and blast resistance, 24 plates and 24 prisms were manufactured as test specimens. A set consisting 0f 8 plates were tested under high velocity impact using 14.7 caliber bullets with a shooting distance of 63 m. The specimens with 1.5 % steel fiber and two layers of steel mesh (8 mm at 75 mm) have shown resistance to full perforation of the bullet. Improvements to the resistance to spalling, scabbing and crack growth have also been observed. Field blast testing was carried out on a second set of 8 specimens by using a charge of 100 gm located at the center of each specimen. All the plates were 160 mm thick and with had minimum reinforced of 0.75% glass fiber and a single layer of steel mesh (8 mm at 75 mm). Have shown resistance to full perforation of waves and have restricted the number, the width and the growth of cracks. The last set of the remaining 8 plates was subjected to a low speed impact test performed by a falling steel ball. Test results clearly show the significant effect of using steel and glass fiber besides deformed bars to enhance the impact resistance by 400 % and 20 % by using 1.5 % steel fiber and 0.75 % glass fiber resistance .Energy absorption capacity and ductility were also increased by 100 % and 600 % by using 1.5 steel fiber. Chang in compressive strength of about ±6 % and ± (20 – 30 ) % were observed by using 1.5% steel fibers and 0.75% glass fibers respectively. The inclusion of 1.5% steel fibers and 0.75% glass fibers together with deformed steel bars have improved the tensile strength by 200% and 70% respectively.