Statistical assessment of a design formula for the debonding resistance of FRP reinforcements externally glued on masonry units

The present work aims to statistically assess a new design procedure to estimate the bond resistance of composite fabrics externally glued on masonry substrates. A database of experimental campaigns of bond test results between fiber reinforced polymer and masonry is collected and, after an overview of the design rules at disposal, an alternative formula is proposed starting from theoretical and experimental evidences. The main parameters influencing the ultimate load are defined through a correlation analysis and different assessment approaches are accounted for. Finally, the capabilities of the proposed approach are statistically evaluated and the advantages with respect to existing formulas are discussed.