Tensile strength of finger joints made of Manilkara huberi wood for use in glued laminated timber

Abstract The use of glued laminated timber structural elements requires an experimental study of combinations of wood species and the adhesives used. This aim of this study was to investigate the wood species-adhesive combination in the tensile strength and failure modes of Manilkara huberi wood species manufactured with and without finger joints. The assemblies were made with untreated layers of wood with approximately 12% moisture using the polyurethane-based mono-component adhesive model Purbond HB 712. The amount of adhesive used in the finger joint was a single line of glue with 200g m-2 and pressure of 10 MPa. After 07 days of curing the adhesive, tensile tests were performed on specimens with and without finger joints, allowing the assessment of the efficiency of the joints also through variance analysis. The results of the tests revealed the ineffectiveness of the interface between the adhesive and the Manilkara huberi wood, since the rupture occurred on the glue line, configuring a type 1 failure mode, representing the worst rupture situation.