WOOD RESEARCH Volume 70, Number 1, 2025
GÁBOR ORBÁN and ANTAL KÁNNÁR

ASSESSING THE DISMANTLED GLUED-LAMINATED STRUCTURE OF A NATATORIUM AFTER 35 YEARS IN SERVICE

The article describes the results of the investigation of the load-bearing capacity of the recently dismantled roof structure of the Csik Ferenc Natatorium in Sopron, Hungary, after 35 years of service. The investigation was aimed at measuring the tensile strength perpendicular to the grain, shear strength and global bending strength of the beams and comparing it to the appropriate design stress values. The results showed that the tensile and shear strength of the beams fulfilled the criteria of the Eurocode 5 standard. The bending strength of the full size beam meets the Eurocode5 design strength requirements for strength class GL 36h. The bending MOE does not fulfil the criterion for this strength class, but is higher than the mean value of a GL 24h beam

WOOD RESEARCH Volume 63, Number 6, 2018
ANTAL KÁNNÁR, LASZLO TOLVAJ, and Endre Magoss

Colour change of photodegraded spruce wood by water leaching

Spruce samples (Picea abies Karst.) were irradiated by strong ultraviolet (UV) light emitter mercury lamp and another series of specimens were treated with the combination of UV radiation and water leaching. The total duration of UV radiation for both series of specimens was 50 days. The colour parameters (CIE L*, a*, b*) were measured and evaluated after both UV radiation and water leaching. The increase of redness value was two times greater than the yellowness increase based on the initial value at the end of 50 days treatment. The leaching partly removed the yellow and red chromophore molecules generated by the UV radiation. The samples become slightly lighter after water leaching. The leached samples increased slightly more in yellowness and redness during the first 4-6 days of UV radiation than those of the dry series. The change of surface roughness of the specimens was monitored by diffuse reflectance infrared spectroscopy, because the change of roughness alters the light scattering properties of the surface. The roughness of the samples increased during the UV irradiation, and the tendency of roughness change mirrored that of yellowness change. The leaching reduced the roughness value in all examined cases. Good correlation was found between the hue angle and the lightness in both dry UV treatment and combined UV treatment and water leaching.

WOOD RESEARCH Volume 66, Number 2, 2021
ANTAL KÁNNÁR and Csilla Csiha

Comparative analysis of static and dynamic MoE of pannónia poplar timber from different plantations

The aim of this study has been to investigate the suitability of Pannónia poplar (Populus × euramericana cv. Pannónia) timber for structural purposes. Static and dynamic modulus of elasticity (MOE) has been determined on samples of 4 different Hungarian plantation origins. The results of the dynamic test showed the same range as the static test, showing a good correlation of the two measurements. As result it can be stated that the domestic Hungarian Pannónia poplar species have in average 11000 N.mm-2 modulus of elasticity. This exceeds considerably the threshold limit value (7000 N.mm-2) necessary for structural applications according to Eurocode 5. Therefore Pannonia poplar is suitable for structural applications, and are a good alternative of the widely used coniferous species in construction sector.