Experimental assessment of glulam beams made by European beech from Spain

The demand for engineered wood products for construction and the climate change affecting some forest plantations impacts the need for diversifying the matrix of wood species apt for structural applications, which is nowadays focused on a few softwood species. Hardwoods have been considered all over the World by the scientific community and industry players with a special focus on hardwoods such as chestnut, oak, birch, maple, and beech. The present article addresses the experimental assessment of the mechanical and bonding performance of glulam beams made by European beech (Fagus sylvatica L.) from Spain. A total of 48 glulam beams (homogeneous and combined) have been produced at the laboratory facilities (20 without finger joints and 28 with finger joints). Non-destructive tests were previously considered to characterize the raw material using a longitudinal vibration method (Machine Timber Grader), also applied to the glulam beams before the failure test. For the prediction of the mechanical properties (modulus of elasticity), the Transformed Section Method and Longitudinal Vibration Method were considered. Correlation coefficients of 0.90 or higher have been obtained. Additionally, 41 lamellas with finger joints have been characterized by tension, resulting in a characteristic tensile value of 50.8 MPa. Its influence on the bending properties of the glulam beams has been evaluated, obtaining a characteristic bending strength value of 52.9 MPa. In general, a good bonding performance has been obtained for both Method A and Method C protocols from the European standard of glulam manufacturing (EN 14080).