Flexural and shear/punching strengthening of RC beams/slabs using hybrid NSM-ETS technique with innovative CFRP laminates

Abstract

In this study, the potentialities of an innovative hybrid technique for the simultaneous flexural and shear/punching strengthening of existing reinforced concrete (RC) beams/slabs are experimentally assessed. This hybrid strengthening technique combines the NSM technique for the flexural strengthening and ETS technique for the shear/punching strengthening purposes in the same application using new U-shape CFRP laminates. For this purpose, two experimental programs composed of RC beams and RC slabs were executed for a first assessment of the strengthening potentialities of this hybrid technique and CFRP laminates. The obtained results for the tested RC beams evidence that the proposed hybrid technique provides, in addition of simultaneous flexural and shear strengthening and better bond performance for the ETS and NSM CFRPs, a higher resistance to the susceptibility of occurring premature failure modes. Moreover, this technique provided a significant improvement in terms of ultimate load carrying and deflection capacity of RC slab.