Bond quality at the FRP-wood interface using wood-laminating adhesives

Fibre-reinforced polymer (FRP)-strengthened glulam would be a more economically viable product if a single adhesive type could be utilised at all the bonded interfaces. This paper describes a test programme that examines the hygrothermal compliance of five commercial wood-laminating adhesives when bonding commercially viable FRP materials to wood. It was seen that the integrity of the bond depended not only on adhesive type but also on the FRP type under consideration. For one of the FRP types, moisture-cycled FRP-wood bonded specimens obtained high wood failure percentages and good shear strength results that compared well with non-moisture-cycled FRP-wood specimens, non-moisture-cycled wood-wood bonded specimens and solid control specimens taken from the same board. This encouraging result suggests an alternative to the expensive structural epoxy adhesives, which are generally accepted as the appropriate adhesive in FRP-strengthened glulam.