Structural performance evaluation of finger-jointed rubberwood manufactured by factories in Thailand

Abstract

In order to utilize finger-jointed rubberwood as raw material for the production of structural wood products, the finger joint efficiencies of rubberwood specimens taken from three factories in Thailand were evaluated. This study investigated the finger profile, modulus of rupture (MOR), and modulus of elasticity (MOE) of finger-jointed rubberwood from all selected factories. The effect of finger orientations (vertical and horizontal) on MOR and MOE values was also examined. The results showed that all selected factories used the same finger profile for manufacturing finger jointing of rubberwood samples. The finger orientations had no noticeable effect on the MOR and MOE values. The MOR values of finger-jointed rubberwood obtained from all selected factories were different. They ranged from 55 to 78 MPa. A primary cause of failure for specimens with lower MOR values was the poor surface bonding of fingers. The MOE values of samples were similar for all selected factories ranging from 9,710 to 12,200 MPa. According to BS EN 338 (2016), finger jointed rubberwood from some factories was inappropriate for production of high strength structural wood products.