| This study focused on replacing conventional unsustainable resins currently used in the fabrication of externally bonded Fibre Reinforced Polymers (FRP) with bio-based resins. The first two phases of this study explored three partially bio-based resin blends, namely; one with 41% of its content derived from vegetable and wood industry by-products (VW), a cashew nut shell liquid (CN) resin blend and an epoxidized linseed oil (ELO) resin blend. The mix ratios with epoxy were varied to obtain 20 to 40% bio content for the CN resin, and 10 to 40% bio content for the ELO resin. Both glass (G) and carbon (C) fibres were investigated.;Ninety tension coupons and sixty lap splice specimens were tested as part of the first phase of this study. The VW specimens had mean tensile strength (fu) within 9% of the epoxy (E) FRP specimens. The CN30%-CFRP specimens had a similar fu compared to the E-CFRP specimens, while the CN40%-GFRP specimens had a fu, 15% lower than the E-GFRP specimens. ELO20%-CFRP specimens had a fu similar to the E-CFRP specimens and the ELO30-G specimens had a fu, 13% higher than the E-GFRP specimens.;In the second phase, small concrete beam bond test specimens were tested to compare FRP bond strengths. It was found that the VW resin, with the highest bio content of 41%, had similar bond strength compared to epoxy. The ELO resin with 20% bio content showed the highest bond strength, at 30% higher than epoxy. The CN resin, at 20 to 30% bio content, resulted in comparable bond strengths compared to epoxy.;This final phase examined the effects of freeze-thaw (FT) cycling on both FRP coupons and large-scale reinforced concrete beams with externally bonded FRPs fabricated with three different resins -- a furfuryl alcohol fully bio resin, an epoxidized pine oil partial bio resin and the E resin. The FT conditioning was found to have minimal effects on the tensile strength and modulus of the FRP coupons. For the beams, the ultimate strengths after FT conditioning increased by 7 to 17%, likely due to the additional concrete curing during thawing in water. |
