WOOD RESEARCH Volume 68, Number 3, 2023
Sumanta Das, Miroslav Gašparík, Anil Kumar Sethy, Peter Niemz, Rastislav Lagaňa, Tomáš Kytka, Martin Sviták, and Gourav Kamboj

Suitability of Aspen (Populus Tremula L.) for Cross-Laminated Timber (CLT)

Cross-laminated timber (CLT) CLT is an excellent material for building and high load-bearing structural applications, but its fabrication and use are limited to softwood only. The suitability of aspen (Populus tremula L) wood for manufacturing CLT was assessed by using two adhesives, one-component polyurethane (1C-PUR) and melamine adhesive (ME). Physical properties like water absorption (WA), thickness swelling (TS), delamination, and mechanical properties like bond shear strength, bending modulus of elasticity, bending strength, and rolling shear strength were evaluated to examine its suitability. Compared to ME-bonded CLT, 1C-PUR bonded CLT panels displayed superior physical characteristics, with 70% passing the delamination test. CLT panels bonded with 1C-PUR adhesive also have better mechanical properties than ME-bonded CLT. CLT panels experienced three types of bending failure: rolling shear, delamination, and tension. Aspen CLT has similar or higher mechanical properties than traditional softwoods, making it suitable for CLT manufacturing.

WOOD RESEARCH Volume 61, Number 1, 2016
Ergün Güntekin, Tuğba Yilmaz Aydin, and Peter Niemz

Some orthotropic elastic properties of Fagus orientalis as influenced by moisture content

The aim of this study was to investigate the influence of moisture content on some orthotropic elastic properties of Oriental beech (Fagus orientalis). The elastic properties investigated include EL, ER, ET, νLR, νLT, νRL, νRT, νTL and νTR under compression. Compression strength in all orthotropic directions was also studied. Specimens were cut from sapwood of beech logs and sorted into four matched MC groups. Clear wood samples were conditioned at 20°C and 50, 65, 85, 95 % RH and subjected to compression tests. A digital image correlation technique was used to capture the strains during testing. Young modulus, Poisson ratios, and compression strength were calculated and compared for all orthotropic directions. Results indicated that Young modulus and compression strength of the samples tested were strongly affected by moisture content. Poisson rations seem to less sensitive to the MC changes.