Bond Performances of SRG Composites: Experimental and Numerical Investigation

The Steel Reinforced Grout (SRG) composite system represents a newly developed promising technique for strengthening existing reinforced concrete and masonry structures. The SRG composite was comprised of steel fiber strips embedded within two layers of inorganic matrix. Nevertheless, the matrix is responsible for the stress-transfer in composites. The experimental results present in literature show a slippage of the fibers and fracture of the external matrix layer at the fiber-matrix interface. This is a critical phenomenon in structural strengthening applications. The present paper presents the results of an experimental and numerical investigation on the bond performances of the SRG system bonded to concrete substrate. The FE analysis was developed using Abaqus-code with a bond slip model present in literature. In addition, the aim of the FE analysis was to predict the behavior of concrete joints strengthened with SRG composites. The parameters of the bond slip model law were calibrated on the results of the experimental campaign. The experimental campaign was focused on the concrete joint strengthened with SRG, in particular, the tests were conducted by a single lap direct shear test varying the bonded length. Finally, the comparison between the numerical and experimental curves was carried out in terms of peak load.