bonding strength of thermally treated spruce (picea abies) and oak wood

Thermally modified wood has been widely reported to have improved durability and aesthetic appeal than its natural counterparts in same economic range. Due to this, there has been a constant effort to utilize its durability properties in different commercial products. Utilization of outer layer thermally modified wood on exposed surface is a classical idea, but bonding of thermally modified to natural wood has been a challenging part and needs extensive investigation on different species. In this study, we tried to investigate bonding properties of oak wood with thermally modified wood (spruce) and compared it with natural oak – oak bond strength. We observed a significant decrease of 47% in value of shear strength for thermally treated wood with natural wood when compared with natural oak – oak bonding. Thermally treated wood can be used as outermost layer in those products, where shear strength does not play a crucial role and more research is required to improve its bonding with natural wood to increase its applicability range.