Responsible partners: SerQ (Portugal) and Cesefor (Spain)
Collaborative partner: Ademan (Spain)
Description: The technological advances within the last decades have increased significantly the use of timber in construction, mainly through the development of high structural performance products compared to the performance usually achieved with sawn wood. Examples of highly used high-performance timber-based products are: glued laminated timber (glulam), cross-laminated timber (CLT), plywood among others, which allow the design of higher span, better aesthetic and structural performance.
About glulam, due to the abundance of raw materials and ease of work, softwood species (e.g. Spruce and Scots pine) have been the most commonly used for glulam fabrication. This excellency product has a century of scientific and technological development, both in terms of raw-material characterization, adhesives for assembly, as well as standards that establish the requirements for manufacturing, characterization and quality control of the product and its components.
Given the advances and the interest and potential of hardwood species for use in glulam, one of the goals of the Eguralt project is the study of high-performance glulam solutions using local hardwood species. This Experiment is directly related to Experiment number 6.
To achieve the main objective of this experiment, it was divided into three main tasks:
- Non-destructive characterization of the raw material;
- Mechanical characterization of glued laminated timber beams (bending tests);
- Bonding performance assessment.
The non-destructive characterization of the raw material is a key topic as it is essential to assess the quality of the lamellae and to allow for the predictions of the mechanical properties of the beams even before they are produced (based on analytical prediction models). This process follows Experiment number 6 and will be applied to Poplar and Beech (mainly 2nd quality according to current sawmills criteria), among others if possible.
After the assembly process, which will take place in a controlled environment (temperature and relative humidity) as prescribed in the EN 14080, and considering the most suitable processes for adequate performance (lamellae thickness, adhesives, assembly time, among others). The adhesive curing process is ensured and subsequent mechanical bending tests are carried out to determine both moduli of elasticity and bending strength (EN408).
Finally, after destructive tests, specimens will be cut for bonding performance assessment through delamination tests (EN 14080 – Annex C) and glue lines shear tests (EN 14080 – Annex D).