PRELIMINARY STUDY ON BULLET RESISTANCE OF DOUBLE-LAYER CONCRETE PANEL MADE OF RUBBERIZED AND STEEL FIBER REINFORCED CONCRETE

Abstract

In this study, the impact resistance of double-layer concrete panels made
of rubberized and steel fiber reinforced concrete subjected to direct fire
weapon (11 mm or .44 Magnum bullet size) is investigated. Concrete
panels with dimensions of 400x400x50 mm are subjected to impact forces
from 11 mm-diameter bullets at a distance of 10 m. Three types of
concrete panels are tested: single-layer steel fiber reinforced concrete
(SFRC), single-layer crumb rubber concrete (CRC) and double-layer
CRC/SFRC. For a double-layer CRC/FRC, the CRC layer of 12.5 mm is
added to the front surface to partially replace part of the SFRC panel. It is
expected that, with its high elasticity and flexibility, the CRC layer will
act as a cushion layer to absorb impact energy from the bullet and reduce
the damage to the concrete panel. During the impact event, the
acceleration of the plate is measured using an accelerometer. The
measured acceleration is then used for calculating the force acting on the
plate and also its displacement.