Bond Behavior of FRCM Composites Applied on Concrete and Masonry

Fiber Reinforced Cementitious Matrix (FRCM) composite materials have been recently introduced in civil engineering applications for the strengthening of masonry and reinforced concrete elements. The aim of the presented experimental study is to evaluate the bond behavior of carbon and glass FRCM composite materials, in the form of bidirectional grids or unidirectional sheets, applied on different substrates by using a cementitious mortar together with an adhesion promoter. Experimental outcomes obtained on masonry using a cementitious mortar have also been compared with the results coming from the same strengthening systems applied with lime mortar. All specimens were subjected to single-lap shear tests until failure, in order to evaluate failure modes, maximum bond capacity and the whole samples behavior in terms of displacement and strain maps (thanks to Digital Image Correlation technique). Experimental outcomes highlighted the good performance of the strengthening systems tested when applied in combination with the adhesion promoter.