Strengthening of reinforced concrete beams in shear using different steel reinforced grout techniques

In this study, steel reinforced grout (SRG) is proposed for shear strengthening of reinforced concrete (RC) beams using the near-surface embedded (NSE) technique. It is believed based on several research contributions in the literature that the NSE technique precludes or delays the onset of premature debonding and achieves higher strength increase in strengthened beams compared to the externally bonded (EB) counterpart. The tests conducted in this study used 13 RC beams to determine the shear behavior of RC beams strengthened in shear using SRG. The effect of the strengthening technique (NSE versus EB), SRG fabric density, strengthening scheme (side-bonded vs. U-wrapped), and the strengthening configuration (continuous vs. discontinuous) on RC shear enhancement was studied. The strengthening effectiveness of the SRG system was assessed in terms of the shear capacity, failure mechanism, load-deflection response, and strain results. The NSE-SRG increased the beam shear strength by an average of 100%, alleviated SRG debonding, and enhanced the deformation characteristics. The average increase in the shear strength of the EB-SRG strengthened beam was 54% and 105% for the continuous and discontinuous SRG strips, respectively. An analytical model is proposed to predict the shear capacity of both the NSE-SRG and EB-SRG strengthened beams and give accurate and safe predictions.