Mechanical properties of laminated veneer lumber produced from ten cultivars of poplar

Peeling industry is the most important outlet for poplar resource composed of many cultivars. A comprehensive evaluation of wood quality of these different cultivars is necessary for a better knowledge of their suitability for innovative applications, like LVL for construction, in order to help foresters in their choices. This research participates to this approach, focusing on mechanical properties of LVL boards produced from ten cultivars, having grown in four different soils. Two trees were harvested per soil type and per cultivar; the tests were performed on eighty trees, which were peeled 1.4 mm thick and 3 mm thick. The produced veneers were used to manufacture 160 LVL boards using two adhesives: polyvinyl acetate (PVAc) and melamine–urea–formaldehyde (MUF). Each board was characterized by non-destructive and destructive mechanical tests, measuring their density, modulus of elasticity and modulus of rupture. The results show that the boards’ mechanical performance is neither linked to veneer thickness nor adhesive type. No cultivar or soil effect was clearly identified. The studied cultivars are not suitable for structural applications. Nevertheless, a discussion about an increase in the poplar rotation duration seems relevant in order to be able to use this wood for construction.