FRP Strengthening of Masonry Columns: Experimental Tests and Theoretical Analysis

Structural rehabilitation involving upgrading of existing structures and buildings conservation has becoming increasingly important. In this paper an experimental campaign on natural stone masonry columns axially confined by fiber reinforced polymers (FRP) is presented and discussed. Two different FRP wrapping system have been used: CFRP (carbon-fiber-reinforced polymer) embedded in epoxy resin, and FRMC (fiber-reinforced-cementitious matrix) embedded in two layers of a special mortar acting as bonding agent. A comparison between the two systems has been carried out. Results show that the ultimate load, stiffness and ductility significantly increase compared with unreinforced columns. Pre-damaged columns strengthened with CFRP and FRCM recover their load bearing capacity and improve their ductility. In addition, experimental results have been compared to theoretical strength previsions provided by literature analytical models, and findings have been analyzed and discussed.