Birch for Engineered Timber Products: Part II

Even though birch (Betula pendula) is one of the main tree species in the north of Europe, it is currently hardly used for structural products, except plywood. Due to its excellent mechanical properties, the HASSLACHER group decided to see it as a future tree species for their products. In a series of projects, the material was characterised and products like Glued Laminated Timber (GLT) or Cross Laminated Timber (CLT) made from birch were developed and tested. To improve the properties of the material, a new type of lamella was developed and tested, the so-called “Strip Lamella”. By using homogenisation effects, the characteristic values of the mechanical properties were strongly improved compared to birch solid wood lamellas. First tests on GLT beams out of Strip Lamella show, that this effect not only occurs in the lamella, but also in structural timber products using this lamella, leading to higher properties compared to birch solid timber GLT.