Blast response of RC slabs with externally bonded reinforcement: Experimental and analytical verification

The present paper provides an analysis of the efficiency of externally bonded reinforcement (EBR) on reinforced concrete (RC) slabs under blast loads. Five simply supported slabs with a span of 2 m are tested under explosive charge. One of the slabs is used as a reference specimen and the remaining slabs were strengthened with different ratios of carbon fiber reinforced polymer (CFRP). An analytical analysis is carried out using the simplified single-degree-of-freedom (SDOF) approach to predict the maximum deflection at midspan. Digital image correlation (DIC) is used to measure the maximum deflection at the midspan of the slab and the strain distribution in the concrete and the EBR. Given the challenge to combine these displacement field measurements with blast, an explosive driven shock tube method has been adopted in this study. The results indicate that CFRP as EBR increases significantly the flexural capacity and the stiffness of RC slabs under blast loads. The impact of the blast wave on the RC slabs generates high strains in concrete, steel reinforcement and CFRP strips. Good correspondence in the prediction of the maximum deflection between the experimental and the analytical results, is obtained, showing that analytical analysis by means of the simplified SDOF approach leads to a reliable prediction.