Comparison between homogeneous beech and hybrid beech-silver fir glulam beams made with short supply chain timber

The growing request of timber for high performance constructions coupled with the depletion of conifer resources due to the ecosystem modification caused by global warming, makes it necessary to explore alternative supply sources. Additionally, the increased emphasis on sustainability within the supply chain has strongly influenced the worldwide relaunch of small local businesses, aiming to provide regionally sourced materials while reducing environmental impact and fostering economic resilience. This study investigates the mechanical properties and bonding quality of homogeneous beech and hybrid beech-silver fir glulam beams produced using short supply chain timber from Southern Italy. This research aims at demonstrating the feasibility of a local production using underused hardwood species as beech. Mechanical characterization included bending and shear tests, as well as evaluations of finger joint and glue line performance. The achieved evidence demonstrated the goodness of both configurations that meet or exceed the standards for structural timber. In particular, the hybrid configuration proved to have comparable mechanical properties for homogeneous and hybrid beams while being lighter and more material-efficient. Bonding quality assessments revealed that finger joints performed satisfactorily for both species, with values exceeding the characteristic strength of the respective timber grades. Glue line strength was comparable to other literature results, though homogeneous beech beams faced challenges in delamination resistance, highlighting the need for further adhesive optimization. Conversely, hybrid beams exhibited superior bonding durability, effectively addressing hardwood gluing challenges. This research proved the potential of hardwood use for the realization of engineered products for structural applications; it also highlights the potential of hybrid configurations in optimizing material performance to realize high-performance structural components while supporting local timber supply chain. Future research should refine bonding techniques for hardwood glulam and explore alternative adhesives to further improve durability and performance.