Structural behaviour of RC beams externally strengthened in flexure with SRG and SRP systems

This paper presents the results obtained from an experimental investigation carried out on a set of reinforced concrete beams strengthened in flexure by using an unidirectional high-strength carbon steel fibre reinforcing mesh embedded in an inorganic matrix (SRG: Steel reinforced grout) and in an organic matrix (SRP: Steel reinforced polymer). Test parameters include the use or not of external U-wrap end anchorages in order to prevent delamination premature failure of the longitudinal sheet and to evaluate the effects on strength and ductility of the strengthened beams. A theoretical study to evaluate the failure loads and material strains of the strengthened beams was also carried out according to the guidelines ACI 440.2R-08 and CNR-DT 200 R1/2013 available for the fibre reinforced polymer systems. The experimental and theoretical analysis of the strengthened beams allowed to evaluate the effectiveness of the two external strengthening systems (SRG and SRP) in increasing the load carrying capacity and to highlight the role of external U-wrap end anchorages on the overall structural behaviour of the strengthened beams.