Bond Behavior of Steel Cords for SRG Systems to Cementitious and Lime Based Mortar
Francesca Roscini, Maurizio Guadagnini
Abstract
Over the past two decades, different innovative systems have been developed for the rehabilitation and retrofitting of existing structures. In particular, SRG (Steel Reinforced Grout) strengthening systems have proven to be very effective in increasing the load carrying capacity and global ductility of reinforced concrete and masonry structures, and their use as an alternative seismic retrofitting solution is increasing rapidly. Although several studies have focused on the characterisation of the mechanical performance of SRG composites subjected to direct tension or bonded to concrete/masonry substrates, the local bond behaviour of steel cords to mortar, which is critical for the overall structural performance of these composites systems, needs to be examined in more depth. To this end, a series of pull-out tests was carried out to study the bond stress transfer of high strength galvanized steel cords embedded in two types of inorganic matrices, including a cementitious and a lime based mortar. In addition, the steel cord to mortar bond was examined through the implementation of a surface-based cohesive contact model in a non-linear finite element framework and the distribution of stresses within the mortar surrounding the steel cord was analysed.