Application of non-destructive methods for predicting the modulus of elasticity in glued laminated Eucalyptus timber beams

Abstract

Engineered wood products, such as glued laminated timber (Glulam), are an attractive option from a sustainability standpoint, in addition to allowing the application of small-sized pieces to achieve large-sized structural elements. In this context, the objective of this study was to determine the mechanical properties, through non-destructive testing, to evaluate the behavior of Glulam beams produced with Eucalyptus urophylla × Eucalyptus grandis clone wood. The study was carried out on 12 Glulam beams produced with melamine-urea-formaldehyde (MUF), resorcinol-formaldehyde (RF), and polyurethane (PUR) adhesives, with four beams per adhesive. The modulus of elasticity (MOE) of the Glulam beams was obtained using non-destructive techniques, with transverse vibration, longitudinal vibration, stress wave tests with Fakopp and Metriguard, and static bending. The results showed a significant correlation between the moduli of elasticity obtained by the transverse vibration test and the static bending test ( R  = 0.82). Therefore, the transverse vibration method proved to be a reliable technique for estimating the modulus of elasticity. Furthermore, it was possible to conclude that Eucalyptus urophylla × Eucalyptus grandis wood, associated with MUF, RF, and PUR adhesives, shows potential for application as structural Glulam beams.