Portuguese forests have changed in recent years. These changes were mainly boosted by the wildfires that affected a significant percentage of the softwood area. Eucalyptus is actually the dominant wood species in Portuguese forests. This is not a native hardwood, but is being planted mainly for pulp and paper production, and its availability and mechanical performance have made it very present in timber construction in the last 50 years. Within the discussion to substitute imported raw materials, mainly from softwoods, with local hardwoods for the production of engineered wood products, the study of the ability to glue eucalyptus has become a necessity. This paper presents experimental works aimed to assess the ability to glue eucalyptus elements for the production of glued laminated timber (GLT) and cross-laminated timber (CLT). Since this wood species has been known for being difficult to dry, a preliminary study on the dimensional stability under moisture content variation was performed. Then, shear strength tests were made in accordance with ASTM D143. The objective was to correlate those results with the tests performed in the following research step. In this further stage, shear strength tests of the bond line were performed following EN 14080 and EN 16351. The results obtained in all the experiments show that eucalyptus has the potential to be glued and therefore the production of GLT and/or CLT using this local undervalued wood species is potentially of high industrial interest.

Engineered wood products (EWPs) have evolved over time to become a popular and sustainable alternative to traditional lumber by offering design flexibility, increased strength, and improved quality control. This work analyzes the potential of Portuguese eucalyptus wood (Eucalyptus globulus) to produce glued-laminated timber (glulam) for structural applications. Currently, this hardwood is used for less noble applications in Portugal’s construction industry. To promote the use of this species of timber in construction, an experimental campaign was conducted to characterize its compression parallel to the grain and bending strength. The results demonstrated that this hardwood presents a compression parallel to the grain strength of 73 N/mm² and a bending strength of 151 N/mm² with a global value of elastic modulus equal to 24,180 N/mm². Based on those strength values obtained from the glulam produced with eucalyptus, one can conclude that the test results presented here are higher than the ones declared by the current glulam made of softwoods; thus, additional studies are encouraged.

The wood of Albizia glaberrima demonstrates favourable attributes for nailing, screwing, and gluing. It exhibits moderate durability and resistance to termites though it is susceptible to specific borers. A comprehensive research initiative was undertaken to increase its suitability for structural purposes. The research encompassed non-destructive and destructive testing methodologies to evaluate mechanical properties, including bending and tension characteristics, while also assessing physical properties such as density and moisture content. The results of this study unveiled that A. glaberrima possesses a relatively light density, averaging at 530 kg/m³. The dynamic elasticity module ( E _din ) exhibited a range between 10,315 N/mm² and 13,662 N/mm², contingent on the specific non-destructive method employed. Bending strength ( f _m ) was determined to be 63 N/mm², while tensile strength ( f _t,0 ) measured at 56 N/mm². The local and global values of the elastic modules in bending ( E _m,l and E _m,g ) were established as 14,487 N/mm² and 10,270 N/mm², respectively, whereas the corresponding value for tension ( E _t,0 ) recorded a value of 14,412 N/mm². These findings substantiate the inherent potential of Albizia glaberrima wood for structural applications.