A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
An Assessment of Environmental Impact on Glued Wood Building Elements ; Procjena utjecaja okolišnih uvjeta na lijepljene drvne elemente u graditeljstvu
The research investigated the impact of environmental factors (temperature and humidity) on pine glulam, oak glulam, and laminated veneer lumber (LVL) elements, all of which can be used in building structures. Elements underwent freezing, heating, drying, and wetting processes in different modes, thereby simulating different environmental conditions that could be encountered during the service period of the materials. Their mechanical properties (modulus of elasticity - MOE and coefficient of damping) were recorded at each stage. It was determined that, in the case of dry construction elements (where a moisture content was between 7.0 and 14.0 %), the MOE increases by a few percentage points with decreasing temperature and humidity levels, and decreases with increasing temperature and humidity levels. The coefficient of damping varied by 20 % - in most cases, when the modulus of elasticity increased, this decreased, and vice versa. Under extreme environmental changes (with the elements being soaked, frozen at -25 °C, and dried at 40 °C), the MOE of the glued timber decreased by 16 % when this parameter of LVL decreased by about 10 %. Alterations in viscous properties produced similar results (the coefficient of damping increased by 50 % for the glued timber and by 66 % for the LVL). This is explained by the partial destruction of the element structure, the occurrence of cracks, and the decreased anisotropy of the LVL structure. ; U radu je istraživan utjecaj okolišnih čimbenika (temperature i vlage) na elemente lameliranih nosača izrađenih od borovine i hrastovine te na elemente lamelirane furnirske građe (LVL), koji se često rabe u graditeljstvu. Elementi su bili na različite načine podvrgnuti smrzavanju, zagrijavanju, sušenju i vlaženju kako bi se simulirali različiti okolišni uvjeti koji bi se mogli pojaviti tijekom uporabe tih materijala. U svakoj su fazi ispitivanja bilježena mehanička svojstva promatranih drvnih elemenata (modul elastičnosti – MOE i koeficijent prigušenja). Utvrđeno je da se u suhih građevinskih elemenata (sadržaj vode između 7,0 i 14,0 %) s padom temperature i vlage MOE povećava za nekoliko postotnih bodova, a smanjuje se s porastom temperature i vlage. Koeficijent prigušenja u većini je ispitivanja varirao za 20 %: kako se modul elastičnosti povećavao, koeficijent prigušenja se smanjivao, i obrnuto. Pri ekstremnim promjenama okolišnih uvjeta (potapanjem elemenata, smrzavanjem na –25 °C i sušenjem na 40 °C) MOE lameliranih nosača se smanjio za 16 %, a LVL-a za oko 10 %. Glede promjena viskoelastičnih svojstava, zabilježeni su slični rezultati (koeficijent prigušenja lameliranih nosača povećao se za 50 %, a LVL-a za 66 %). To se objašnjava djelomičnom razgradnjom strukture drvnih elemenata, pojavom pukotina i smanjenom anizotropijom strukture LVL-a.
An Assessment of Environmental Impact on Glued Wood Building Elements ; Procjena utjecaja okolišnih uvjeta na lijepljene drvne elemente u graditeljstvu
The research investigated the impact of environmental factors (temperature and humidity) on pine glulam, oak glulam, and laminated veneer lumber (LVL) elements, all of which can be used in building structures. Elements underwent freezing, heating, drying, and wetting processes in different modes, thereby simulating different environmental conditions that could be encountered during the service period of the materials. Their mechanical properties (modulus of elasticity - MOE and coefficient of damping) were recorded at each stage. It was determined that, in the case of dry construction elements (where a moisture content was between 7.0 and 14.0 %), the MOE increases by a few percentage points with decreasing temperature and humidity levels, and decreases with increasing temperature and humidity levels. The coefficient of damping varied by 20 % - in most cases, when the modulus of elasticity increased, this decreased, and vice versa. Under extreme environmental changes (with the elements being soaked, frozen at -25 °C, and dried at 40 °C), the MOE of the glued timber decreased by 16 % when this parameter of LVL decreased by about 10 %. Alterations in viscous properties produced similar results (the coefficient of damping increased by 50 % for the glued timber and by 66 % for the LVL). This is explained by the partial destruction of the element structure, the occurrence of cracks, and the decreased anisotropy of the LVL structure. ; U radu je istraživan utjecaj okolišnih čimbenika (temperature i vlage) na elemente lameliranih nosača izrađenih od borovine i hrastovine te na elemente lamelirane furnirske građe (LVL), koji se često rabe u graditeljstvu. Elementi su bili na različite načine podvrgnuti smrzavanju, zagrijavanju, sušenju i vlaženju kako bi se simulirali različiti okolišni uvjeti koji bi se mogli pojaviti tijekom uporabe tih materijala. U svakoj su fazi ispitivanja bilježena mehanička svojstva promatranih drvnih elemenata (modul elastičnosti – MOE i koeficijent prigušenja). Utvrđeno je da se u suhih građevinskih elemenata (sadržaj vode između 7,0 i 14,0 %) s padom temperature i vlage MOE povećava za nekoliko postotnih bodova, a smanjuje se s porastom temperature i vlage. Koeficijent prigušenja u većini je ispitivanja varirao za 20 %: kako se modul elastičnosti povećavao, koeficijent prigušenja se smanjivao, i obrnuto. Pri ekstremnim promjenama okolišnih uvjeta (potapanjem elemenata, smrzavanjem na –25 °C i sušenjem na 40 °C) MOE lameliranih nosača se smanjio za 16 %, a LVL-a za oko 10 %. Glede promjena viskoelastičnih svojstava, zabilježeni su slični rezultati (koeficijent prigušenja lameliranih nosača povećao se za 50 %, a LVL-a za 66 %). To se objašnjava djelomičnom razgradnjom strukture drvnih elemenata, pojavom pukotina i smanjenom anizotropijom strukture LVL-a.
An Assessment of Environmental Impact on Glued Wood Building Elements ; Procjena utjecaja okolišnih uvjeta na lijepljene drvne elemente u graditeljstvu
Albrektas, Darius (author) / Ivanauskas, Ernestas (author)
2021-01-01
Drvna industrija : Znanstveni časopis za pitanja drvne tehnologije ; ISSN 0012-6772 (Print) ; ISSN 1847-1153 (Online) ; Volume 72 ; Issue 1
Article (Journal)
Electronic Resource
English
DDC:
690