Modeling and numerical analysis of the bond behavior of masonry elements strengthened with SRP/SRG

Steel Reinforced Polymers (SRPs) and Steel Reinforced Grout (SRG) strengthening systems have been recently introduced as an alternative solution to the traditional systems based on the use of fiber reinforced polymers materials (FRPs). Few studies on SRP/SRG are available in the current literature and all have shown the potentialities of SRP/SRG in improving structural performances of masonry and concrete elements and, at the same time, their difference with respect to FRPs particularly in terms of bond behavior. Aim of the present paper is to propose a simple approach devoted to study the bond behavior of masonry structures strengthened with SRP/SRG systems. The approach, based on experimental evidences and theoretical considerations mainly consists of deriving approximate bond stress-slip laws for the strengthening/support interface layer, able to reproduce the local bond stresses transferring mechanism. Finite Element (FE) analyses are then developed with reference to the experimental tests available in the current literature by adopting the bond stress-slip laws obtained through the proposed approach. The deduced results show the reliability of the proposed approach in simulating the bond behavior of masonry elements strengthened with SRP/SRG and the possibility to investigate further peculiarities characterizing this kind of strengthening systems.