Some considerations on the efficiency of carbon fiber anchors applied on CFRP sheets reinforcements of masonry elements

Several consolidation techniques based on bonding composite materials, and particularly CFRP strips, are more and more used in the past decades for the rehabilitation and the reinforcement of both concrete and masonry elements. A lot of papers in the literature are devoted to the investigation of the mechanical characteristics of the bond interface between the CFRP reinforcement and the structural elements. Nevertheless, these consolidation methods still exhibit some crucial aspects to be clarified, especially for masonry. As it is well known, the key factor characterizing the mechanical behaviour of the CFRP to masonry reinforcement, at least for a collapse analysis, is the bond strength, which strongly depends on the mechanical characteristics of the masonry support. The mechanical properties of CFRP sheet reinforcements can be effectively increased improving the connection mode, for example introducing mechanical anchors as shown in [1]. In this paper the most significant results of an experimental campaign devoted to the analysis of the effectiveness of CFRP reinforcements “nailed” to masonry elements are reported. The experimental results show a significant increase of both the strength and the ductility of this kind of reinforcements with respect to the “simple bonded” CFRP sheets.