WOOD RESEARCH Volume 61, Number 2, 2016
Paola Cetera, Luigi Todaro, Teresa Lovaglio, Nicola Moretti, and Angelo Rita

Steaming treatment decreases MOE and compression strength of Turkey oak wood

This study examined the mechanical properties of Turkey oak (Quercus cerris L.) wood before and after combined steam and thermal treatments under vacuum conditions. Wood was steamed at 100 to 110°C and thermally treated under vacuum at 160°C by the press-vacuum or thermo-vacuum process. Treated material was characterized in terms of the modulus of elasticity (MOE) and compression strength of heartwood and sapwood. The MOE was established using a nondestructive technique based on the measurement of ultrasonic pulse propagation. Results differed depending on the treatment or combination of treatments, and showed that the steaming process strongly affected the MOE. Thermo-vacuum treatment increased the compression strength, whereas steaming had the opposite effect.

WOOD RESEARCH Volume 66, Number 4, 2021
Sahin Akyurek, Murat Akman, and Murat Ozalp

Effects of heat treatment on some chemical compound and mechanical properties of black pine wood

In this study, effects of heat treatment on bending strength, compression strength, chemical compound and solubility of Black pine wood (Pinus nigra J.F. var. seneriana) was examined. For this purpose, Black pine wood samples were kept in temperature of 250°C for 2 hours. Test results of heat-treated Black pine wood and control samples indicated that mechanical characteristics including compression strength and bending strength were affected negatively with heat treatment. Bending strength of heat treated and non-treated test samples were 129 and 76 N.mm-2, respectively. Compression strength of heat treated and non-treated test samples were 53 and 43 N.mm-2, resp. In addition, level of extractives, cellulose and hemicellulose decreased while lignin content increased with percentage of 40%. Significant decreases occurred in all chemical solubility values.

WOOD RESEARCH Volume 65, Number 4, 2020
Laércio Serenini Jr., Rafael Rodolfo De Melo, Diego Martins Stangerlin, and Alexandre Santos Pimenta

Wood quality of six eucalyptus clones planted in northern Mato Grosso State, Brazil

The present work had the goal of assessing the wood quality through physical-mechanical properties of six 5-year old eucalyptus clones currently planted in northern Mato Grosso State, Brazil. The following clones were assessed, five of them Eucalyptus grandis x Eucalyptus urophylla hybrids and one a clone of Eucalyptus camaldulensis. The physical-mechanical properties were basic density as a function of tree height; pith-to-bark direction; linear, tangential and radial shrinkage; and anisotropic coefficient, longitudinal and parallel compression and static bending strengths; and hardness. Eucalyptus grandis x Eucalyptus urophylla hybrids showed the best wood quality. Concerning to mechanical results, the clones reached intermediate values of strength and rigidity, qualifying them for use in structural applications with less stringent requirements. Considering that all the clones had juvenile wood, the mechanical properties were satisfactory, making the clones suitable for industrial uses.

WOOD RESEARCH Volume 65, Number 1, 2020
Marcin Jakubowski, Arkadiusz Tomczak, Tomasz Jelonek, and Witold Grzywiński

Variations of wood properties of birch (Betula pendula Roth) from a 23-year old seed orchard

This work presents the results of selected wood properties in birch trees grown on a provenance experiment plot established as a seed orchard. The study concerned: basic density, oven-dry density and compression strength along the grain at a moisture content of 0% and at moisture content above fiber saturation point. Analyses were performed on 971 wood samples collected from 28 trees at the level of breast height. It was found high variability for diameter of breast height (22%) and relatively low for basic density (9%) and oven-dry density (11%). Average basic density was 446.5 kg.m-3 and average oven-dry density was 537.9 kg.m-3. The compression strength at 0% moisture content was four times higher (65 MPa) than the strength at moisture content above the fiber saturation point (16.6 MPa). Most of clones had similar properties within the limits of statistical errors, but a few clones exhibited statistically significant low value.

WOOD RESEARCH Volume 64, Number 3, 2019
Liuyang Han, Xiu Zhao, Haibin Zhou, and Xiuqin Luo

Reliability analysis on compression strength property of chinese larch visually-graded dimension lumber

The reliability analysis method was investigated in this study to obtain design values of ultimate compression strength parallel to grain (UCS) of Chinese larch visually-graded dimension lumber of common size. A total of 748 lumber samples of 40 by 90 mm were tested for static full-size compression strength according to Chinese National Standards’ requirements of the reliability index. The goodness of fit for the UCS distribution of four visual grades was analyzed and the first-order second-moment reliability analysis under different load cases was performed based on all the test data. The log-normal distribution was the optimizing fitted distribution of the compression strength of Chinese larch dimension lumber. Design values of the compression strength for grades Ic, IIc, IIIc and IVc were suggested for the minimum reliability index. These design values will be recommended to the standard committee of Chinese National Standards.