Your search resulted in 12 documents.
Decay patterns observed in butylene oxide modified ponderosa pine attacked by Fomitopsis pinicola
1983 - IRG/WP 1183
Small blocks of ponderosa pine chemically modified by butylene oxide to three different weight percent gains (WPG) were decayed for 2 months with the brown rot fungus Fomitopsis pinicola. Wood substance loss and the type of decay pattern recognised were fairly similar both for control and blocks treated to 8 and 15 WPG. No difference in attack was observed between radial or tangential walls in lat...
T Nilsson, R M Rowell
Artificial drying of impregnated wood
1987 - IRG/WP 3448
Sawn timber (Pinus Sylvestris) of dimension 50x150 mm was impregnated with CCA by a full-cell process. The timber was then dried in a conventional kiln or a special vacuum kiln where the timber was dried by circulating superheated steam. Drying time was 16 days and 2 days respectively. The aim of the investigation was to compare the physical appearence of the wood after drying by the two methods w...
Characterization of checks and cracks on the surface of weathered wood
2000 - IRG/WP 00-40153
The surface roughness of unweathered and untreated pine; unweathered copper chromium arsenate type C (CCA) - treated pine; weathered CCA-treated pine; and weathered CCA-plus-water-repellent (WR) - treated pine was evaluated by a stylus tracing method. Surface roughness parameters Ra, Rz, Rmax, Rk, Rpk, and Rvk were measured. Ra, Rpk, and Rvk were the most appropriate parameters for describing modi...
D P Kamdem, Jun Zhang
Investigation of the suitability of silver fir (Abies alba Mill.) for thermal modification
2004 - IRG/WP 04-40275
In this study the suitability of silver fir (Abies alba Mill.) was examined for thermal modification. Comparative experimental investigations were performed with silver fir and Norway spruce (Picea abies Karst.) after thermal treatments. Besides properties, which characterize the quality of heat treatments, like dimensional stability and resistance against fungal attack, strength properties of the...
C Brischke, A O Rapp
Preliminary observations of the effect of growth ring orientation on the surface checking of flat sawn Southern pine decking
2005 - IRG/WP 05-20313
Checking in decking timber is a serious defect and methods of reducing its severity are required to ensure that wood can compete with alternative decking materials. The first aim of this research was to test the hypothesis that flat sawn Southern pine decking boards with growth rings oriented concave to the exposed surface will develop less severe checking when exposed outdoors than similarly expo...
K Urban, P D Evans
Cantilever bending test of furfurylated poles
2008 - IRG/WP 08-40424
Ten, 8 m long poles of Scots pine (Pinus sylvestris) were treated with furfuryl alcohol to a WPG of approximately 40 %. A bending test was performed according to the principles in the draft European standard for wooden poles, prEN 14229 - Structural timber - Wood Poles for overhead lines. The bending strength and stiffness (MOE) for the poles tested were compared to an earlier study by the Swedish Wood Preservation Committee. In the latter study untreated, CCA-treated, ammoniacal Cu-PCP treated and creosoted poles were tested in bending. These types of poles were considered not to differ in strength and stiffness. The results of the furfurylated poles fit well with the results from the previous study. The bending strength and MOE values obtained are compared to the upper and lower 95-percentile values of the results from the previous study and all poles treated with furfuryl alcohol fit within this interval.Thus, this study indicates that a treatment with furfuryl alcohol does not result in a decrease of strength or stiffness. Further testing with a larger population of poles is necessary in order to get a statistically reliable result. In addition to further demonstration of the durability, the treatment process must be optimised to ensure full sapwood penetration and measures have to be taken to avoid the serious cracking observed in this trial before furfurylation can be considered for treatment of Pinus sylvestris poles.
R Ziethén, J Jermer, A Clang
Effectos de la intemperización artificial sobre la madera de mezquite (Prosopis laevigata)
2008 - IRG/WP 08-40430
The effects of artificial weathering on Prosopis laevigata wood were studied on eight replicates (150 x 72 x 15mm (l x t x r)) free of knots, cracks and resin. The samples were exposed tangentially to UV light and to water spray during three cycles (1 cycle corresponded 1 week of artificial weathering). The conditioning time between each cycle was thirty days. The effects were measured according t...
A Carrillo-Parra, F Hapla, C Mai
Moisture distribution in glulam beams with natural cracks observed with CT Scanning before and after rain
2013 - IRG/WP 13-20534
The way cracks in outdoor wooden constructions affect durability is an interesting topic, since a certain amount of cracks can always be found naturally in wood and glued laminated wood. The question in this was, can cracks lead water into the wood and thereby increase the risk for decay and reduce strength and service life. Moisture balance, i.e., water absorption and water distribution were stud...
Acceptance levels of surface disfigurement - tolerance to defects of coated wood
2015 - IRG/WP 15-20564
Service life planning (PSL) has become an important issue in performance based building and substantial progress has been made in recent years. The role of predicting the aesthetical service life of wooden building components has been underestimated for quite long time but is recently attracting more and more notice. It is influenced by numerous factors such as discoloration, fading, flaking, crac...
C Brischke, P Kaudewitz
Evaluation of surface cracks on wood – physical assessment versus subjective sensation
2017 - IRG/WP 17-20617
In the presented studies from the University of Goettingen (Study I) and the University of Hannover (Study II), the assessment of cracks with different methods and their acceptance in general as well as depending on different target groups are investigated. The aim was to determine which factors are relevant for a crack evaluation and which visual impression of a wooden surface is tolerable for co...
A Gellerich, C Brischke, L Emmerich, L Meyer-Veltrup, P Kaudewitz
The influence of chemical compounds on wood cell wall to surface cracks
2020 - IRG/WP 20-40908
Degradation due to cracking and dimensional changes caused by drying, have a significantly negative impact on the preservation and durability of wood. Therefore, the prevention of surface cracking, which tends to occur during the drying process, is vital. High temperature set drying is one of the most effective methods for preventing wood surface cracking. It begins with softening the wood at a hi...
R Suzuki, Y Mori, K Yoshihiro, K Yamashita, M Kiguchi
Influence of weathering on surface roughness of thermally modified wood
2021 - IRG/WP 21-40915
Thermally modified wood is exposed to weathering similarly as other wood-based building materials. It has been reported that if thermally modified wood is exposed to weathering, its moisture performance might decrease fairly fast. The aim of this study was to determine whether this phenomenon is associated with crack formations or roughness. Norway spruce, thermally modified spruce, wax-treated th...
E Kerzic, B Lesar, M Humar