László Bejó

The effect of gamma irradiation on the MOE of various species

Gamma irradiation is a simple and effective method to sterilize wood and stop fungal decay. Unfortunately, little is known of the effect of this method on other properties of wood. The purpose of the present study was to establish the relationship between irradiation dosage and the elastic characteristics of wood. The longitudinal and transverse dynamic MOE of five wood species were measured periodically between subsequent irradiation phases. There was a steady decrease in MOE as gamma dosage increased, for all species included. The extent of this decrease was different between the examined species. The experimental data suggests that the MOE of lower density species decreases more sharply than that of higher density ones. Interpolation between the experimental data points shows that the necessary dose for fungal sterilization does not significantly reduce the MOE of the species involved in this study.

CLT hazai I-214 olasz nyár faanyagból

A tobbretegű keresztiranyu ragasztott tomorfa szerkezeti panel (CLT) a konnyűszerkezetes epites viszonylag uj alapanyaga, mely hazankban meg nem elterjedt. Elterjedeset segitene, ha ezt az epitőelemet hazai alapanyagokbol is gyartani lehetne. Kutatasunk celja a CLT elemek hazai nemesnyar alapanyagbol valo gyarthatosaganak vizsgalata volt. Ennek erdekeben egy haromretegű panel gyartasara es hajlitovizsgalatara kerult sor, olasz nyar alapanyagbol, poliuretan ragasztoanyaggal. A vizsgalati eredmenyek azt mutatjak, hogy az olasz nyar CLT szilardsagi tulajdonsagai megfelelőek az alacsonyabb szilardsagi kategoriaju fenyő faanyagnak, azonban a rugalmassagi modulusz ertekei elmaradnak a kivanalmaktol. A nyar alapanyag alkalmas lehet CLT gyartasra, de csak a lamellak előzetes roncsolasmentes minősitesevel, es a jobb anyagok kivalogatasaval, vagy masodlagos nyersanyagkent a fenyő faanyag mellett.