Naravna odpornost, delež ekstraktivov in izbrane mehanske lastnosti že uporabljene jedrovine hrasta

diplomski projekt

Matevž Bregar (Author), Franc Pohleven (Reviewer), Miha Humar (Mentor)

Abstract

Od nekdaj spada les med najpomembnejše gradbene materiale. V času zavedanja podnebnih sprememb, ki jih je povzročil človek, še dodatno pridobiva na pomenu kot okoljsko zelo ustrezen material. Njegova raba ne obremenjuje okolja in je zelo ugodna za bivanje. Namen projekta je bil ugotoviti, kakšne so izbrane lastnosti hrastovine po več desetletjih uporabe. V ta namen smo uporabili približno 150 let star podporni del ostrešja (roka), izdelanega iz hrastove jedrovine. Fungicidne lastnosti smo ugotavljali z izpostavitvijo 5 različnim glivam; Gloeophyllum trabeum, Antrodia vaillantii, Hypoksylon fragiforme, Pleurotus ostreatus in Trametes versicolor. Mehanske lastnosti (upogibno trdnost, modul elastičnosti in tlačno trdnost) smo določili z univerzalnim testirnim strojem Zwick, s tenziometrom pa kapilarni navzem vode. Opravili smo tudi ekstrakcijo po Soxhletu s 3 topili: vodo, 70 % metanolom in cikloheksanom. Stara hrastoina ima slabšo odpornost na lesne glive, najbolj je to izrazito pri delovanju glive G. trabeum. S staranjem pa pada delež ekstraktivnih snovi.

Keywords

naravna odpornost;jedrovina;ekstraktivi;hrast;

Data

Language:	Slovenian
Year of publishing:	2015
Typology:	2.11 - Undergraduate Thesis
Organization:	UL BF - Biotechnical Faculty
Publisher:	[M. Bregar]
UDC:	630*841.4
COBISS:	2407817
Views:	309
Downloads:	85
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Natural durability, extractive ratio and selected mechanical properties of already used oak heartwood
Secondary abstract:	Since ancient times the wood is one of the most important building materials. Because of climate change caused by man the wood is even more important as an ecologically very suitable material for living, and from the environmental point of view. We researched changes of some of the most important characteristics of oak wood. We used about 150 years old supporting part of the roof made from oak heartwood. Fungicidal properties were determined by subjecting the samples to 5 different fungi: Gloeophyllum trabeum, Antrodia vaillantii, Hypoksylon fragiforme, Pleurotus ostreatus andTrametes versicolor. Mechanical properties (bending strength, module of elasticity and compressive strength) were measured with a universal machine Zwick; the capillary uptake of water with tensiometer. We also made extraction by Soxhlet method. We used 3 different solvents: water, 70 % methanol and cycloheksane. Compared with the control oak wood, the old oak depends on the fungi the timber was exposed to. In the old oak wood, according to the control oak, the mass loss is almost 10 times larger after exposure to rusty gilled polypore (Gloephyllum trabeum). With the aging oak capillary uptake of water and mechanical properties suffer minimal or no change. Partial decline with age was observed in the proportion of extractives.
Secondary keywords:	natural durability;heartwood;extractives;oak;
Type (COBISS):	Diploma project paper
Thesis comment:	Univ. v Ljubljani, Biotehniška fak., Oddelek za lesarstvo
Pages:	XI, 37 f.
ID:	11915337