Experimental Behavior of Masonry Columns Confined Using Advanced Materials

Over last years, Fiber-Reinforced Polymer (FRP) wra pping effectiveness has been clearly confirmed especially with reference to concrete structures. Despite evident advantages of FRP based confinement systems that allow preventing brittle failures of members subjected to compre ssive overloads due to static or seismic actions, the use of such technique in the field of masonry has not been fully explored. Thus, the potential of both FRP wrapping and of an innovative technique based on the u se of FRP grid bonded with cementitious mortar to restore structural safety of masonry members have been investigated in the present paper by an experimental work dealing with 12 square cross-section listed faced tu ff masonry columns subjected to uniaxial compression. In particular, three different confinement schemes were experimentally analysed in order to evaluate and compare the effectiveness of the proposed strengthening techniques: 1) uniaxial glass FRP laminates (GFRP); 2) uniaxial carbon FRP (CFRP) laminates; 3) alkali-resist ant fibre-glass grid bonded with a cement based mortar. The main experimental outcomes in terms of specimens’ mechanical behaviour, stress-axial strain relationships and ultimate strains recorded on the reinforcement in th e transverse direction are presented and discussed in the paper. Experimental outcomes showed that the investigat ed confining systems were able to provide significant gain both in compressive strength and ductility of masonry members.