Evaluation and Repair of Blast Damaged Reinforced Concrete Beams

Abstract

Ten reinforced concrete beams were constructed using standard concrete and A 615 Grade 60 reinforcing steel. Eight of the beams were then damaged using C-4 Composite high explosives to replicate the actual damage that a structural element may receive from a small bomb or other explosive device. The damaged beams were then evaluated and four of the beams were determined to have been damaged beyond reasonable repair. Of the other four damaged beams, two were repaired using carbon fiber reinforced polymer (FRP). The two repaired beams, two unrepaired beams, and two control beams were then tested in third-point loading to determine flexural strength capacity. The load-deflection curves for the six beams were then analyzed to evaluate the effect of the FRP repairs. The two repaired beams demonstrated significant improvement in flexural strength over the unrepaired beams and equaled or exceeded the flexural strength of the undamaged control beams. The study demonstrated that fiber reinforced polymers represent a viable option for the repair of blast damaged beams. The FRP repaired beams demonstrated a significant improvement in flexural capacity in comparison to their equivalently damaged counterparts.