Experimental study of blast response of RC slabs with externally bonded reinforcement

The present paper discusses experimental work on the efficiency of externally bonded reinforcement (EBR) on reinforced concrete (RC) slabs under blast loads using an explosive driven shock tube (EDST). This study focuses on four tests which have been performed on simply supported RC slabs retrofitted with carbon fibre reinforced polymer (CFRP) strips and subjected to explosions for the same pressure and impulse. Pressure transducers are fixed at the end of the tube to measure the pressure of each experiment. Maximum deflection and strain distribution in the concrete and CFRP strips are recorded using digital image correlation (DIC) measurements. Due the explosion, the RC slabs are submitted to a dynamic vibration in both directions and during the first inbound displacement phase, the kinetic energy of the retrofitted specimen is stored as elastic strain energy in CFRP strips. All this elastic strain energy stored in FRP strips is violently released as kinetic energy during the rebound phase of the slab. The results indicate that EBR increases significantly the flexural capacity and the stiffness of RC slabs under blast loads.