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Laboratory tests on artificial weathering of Quercus rubra crossties
1986 - IRG/WP 2252
Clear red oak (Quercus rubra) blocks were used to evaluate various types of accelerated aging tests including boil, steaming, and cyclic weathering. It was found that the repeated vacuum and pressure treatment of wood in water, steaming, oven-dry, and freezing appeared to be most effective in reducing the MOE in compression and hardness modules of wood specimens. Red oak crossties which were pressure treated with creosote - coal tar preservative were tested using the cyclic aging technique. This method will be used to establish correlation between short-term accelerated aging test results and long-term in service performance of wood crossties.
P Chow, A J Reinschmidt, E J Barenberg, S L Lewis


Influence of weathering on the mechanical properties and performance of exterior wood coatings
2022 - IRG/WP 22-40951
Three commercial coatings were exposed to artificial (EN 927-6) and natural weathering (EN 927-3) on wood samples. Cracking was visually assessed as well as Persoz hardness. Free films of the same coatings were also exposed to the same weathering tests before their tensile properties were measured. Results show that artificial and natural weathering modified the overall mechanical properties of wood coatings. The elastic modulus and the strength increased whereas the strain at break dramatically decreased from the first hours of exposure. For selecting good performing coatings, our results show that it is useful to consider the variations of the elastic modulus and to calculate the retention of the initial strain at break after weathering instead of considering the strain at break result. A significant increase in the elastic modulus lead to cracking. Coatings performed better when their modulus remained below 400 MPa and their retention in strain at break was higher than 20%. The study shows that short artificial ageing tests (< 500 h) on free films are relevant to highlight changes in strain at break observed in natural weathering. They are therefore a valuable tool in the formulation of high-performance products. The mechanical properties measured using the Persoz hardness test are also interesting to take into consideration in order to anticipate the risk of cracking. For the three coatings, the Persoz hardness increased more or less due to weathering. The results show that coatings with an initial Persoz hardness higher than 80 seconds should not be chosen for wood exposed outdoors because their risk of cracking is higher.
L Podgorski, J-D Lanvin


Performance results of wood treated with CCA-PEG
1986 - IRG/WP 3363
The addition of polyethylene glycol (PEG) to the CCA system has been shown to reduce the surface hardness of poles and ease spur penetration during climbing. This paper addresses the results of tests dealing with preservative retention and penetration, permanence of CCA and PEG, strength, drying rate, and checking characteristics.
W P Trumble, E E Messina


The effect of service life and preservative treatment on the hardness of wooden poles
1989 - IRG/WP 3537
The surface hardness of utility poles is an important parameter which effects the acceptability of the pole as being safe to climb during line maintenance. The current investigation was designed to evaluate how the surface hardness of preservative treated utility poles is effected by the type of preservative, and the age of the poles. Chromated-copper-arsenate (CCA) treated red pine and jack pine poles which had been in place for up to forty years were located in Bell Canada&apos;s system in Ontario, and screened for use in the project. A survey of poles in three locations was made, and data collected on surface hardness using a 6-Joule Pilodyn. Other information recorded included the wood species identified by the brand, and the moisture content (using a resistance type moisture meter). Core samples were removed from each pole for subsequent measurement of preservative retention. The CCA retentions were determined using an X-ray analysis.
E B Jonsson, E M A Nilsson, J N R Ruddick


A study of wood quality of Juglans nigra and hybrid walnut (MJ 209xRA) : durability against Coriolus versicolor, density and MOR
2004 - IRG/WP 04-10522
The study investigated possible effects of harvesting season on some wood properties of Juglan nigra (JN) and a hybrid walnut (MJ209xRA). The samples were taken from trees which were harvested in June July, August, November of the same year, and March in the year after to determine whether there were any significant differences in wood properties as regards the harvesting seasons. In order to test the durability of the 648 wood samples white rot fungus Coriolus versicolor challenge test (EN113 (AFNOR 1994) was applied by using agar culture medium. The bending strength was also determined after a sixteen-week exposure to the above mentioned fungus. The data obtained clearly indicated that the heartwood of JN was more durable than its sapwood. JN sapwood was more durable than MJ209xRA sapwood. The same trend was observed with the Modulus of rupture (MOR : EN 310): the heartwood displayed higher MOR value than the sapwood. Wood density measurements also demonstrated that the wood density values of the sample heartwoods were much higher than those of the sapwoods. Results also illustrated that, from the wood durability point of view, March is the least interesting period for harvesting. June and November, on the other hand, proved to be more favourable periods as regards harvesting. This study clearly indicates that the durability and the strength of the hybrid walnut (MJ209xRA) are lower than those of the walnut (Juglans nigra), and this fact should be considered in the exploitation of hybrid wood.
B Charrier, F Charrier, D P Kamdem, J B Aurel, G Janin


A Preliminary Report on the Properties of Engineered Wood Composite Panels Treated with Copper Naphthenate
2005 - IRG/WP 05-40294
This paper reports on our preliminary investigation of the properties of randomly oriented strandboard which had waterborne or powdered copper naphthenate (CuN) incorporated into the board during manufacture. When compared to zinc borate-treated controls (ZnB), the mechanical properties of strandboard (MOR, MOE, work-to-maximum load, internal bond strength) were not adversely affected by treatment with either form of copper naphthenate. In general, values for mechanical properties followed the trend untreated controls > waterborne CuN = powdered CuN > ZnB. Water absorption and dimensional properties followed a similar trend. This preliminary study suggests that CuN is a viable alternative treatment for engineered wood composites.
J W Kirkpatrick, H M Barnes


Effects of the addition of polyethylene glycol to the CCA-C preservative treatment
1985 - IRG/WP 3337
A modification of the CCA-C wood preservative system for utility poles has been investigated to see if spur penetration into the poles is assisted during climbing. Addition of polyethylene glycol to the CCA system has been shown to accomplish this purpose. This paper addresses the effects of the addition of polyethylene glycol to other physical properties germane to utility poles.
W P Trumble, E E Messina


The use of modulus of rupture and modulus of elasticity in natural durability testing
1997 - IRG/WP 97-20117
Losses in weight, losses in bending strength and changes in elastic behaviour were assessed in a fungus cellar test with beech wood stakes (Fagus sylvatica). Results were gained after 8, 12, 16 and 20 weeks resp . The outcomes show, that the non-durable species beech is very rapidly attacked by fungi and loses up to 60% of its initial bending strength even within the first 8 weeks. Earlier research by Militz et al. (1996) showed that a durable species in the same period and under comparable conditions do not have any strength reduction. An assessment of weight loss lead to mass losses of ca. 20 - 30% within the same period. From the results it can be stated, that the use of MOR instead of or in combination with weight loss assessments have some advantages to the solely use of weight loss assessments. Furthermore, the outcomes show that as a non-destructive method, MOE assessments are a good tool in the prediction of fungal attack. For the inspection of field trials, the dynamic vibration method can offer some advantages, because no laboratory equipment is needed and the measurements only take some seconds. Further research is ongoing to gain more knowledge on the role of varying moisture contents of stakes in field trials on this type of MOE assessment.
L Machek, H Militz, W Gard


The influence of the location of a wood defect on the modulus of elasticity determination in wood durability testing
2004 - IRG/WP 04-20287
This study investigates the influence of the location of a wood failure in stakes upon elastic changes observed in beech specimens with the resonance vibration technique. Natural failures were simulated by artificially created defects at different locations of the test stake. The results indicate that the location of an attack in a stake is important for the measurement outcome. When the attack is located at far ends of a stake, the detected faults are underestimated. Higher losses of modulus of elasticity were recorded with notches in comparison to bore hole defects. The non-destructive vibration approach (dynamic MOE) applied in durability testing offers advantages compared to conventional static techniques.
L Machek, H Militz


A dynamic approach to assess the modulus of elasticity in wood decay testing
1998 - IRG/WP 98-20139
In this study, the changes in elastic behaviour and mass losses of different hardwood and softwood species exposed to decay in a laboratory soil tests were assessed. Wood decay was monitored using different assessment methods, namely: mass loss and changes in elastic behaviours (MOE) determination. Elastic changes were determined by static and dynamic methods, for the latter, acoustic technique was applied. The results obtained show a high correlation between dynamic and conventional static bending measurements of test specimens at different stages of wood decay. The non-destructive assessment of modulus of elasticity assessment proved to be a good tool in the prediction of early stages of wood decay.
L Machek, H Militz, R Sierra-Alvarez


Effects of heat treatment on modulus of elasticity of beech wood
2002 - IRG/WP 02-40222
Heat treatment is the oldest, simplest and cheapest method for reducing hygroscopicity of wood. The heat treatment protects wood against to biological organisms as well as giving wood dimensional stabilization without damaging environment. The effects of heat treatment on modulus of elasticity (MOE) of beech wood (Fagus orientalis Lipsky) naturally grown and intensively used in forest products industry in Turkey were determined. The wood samples were cut into 2 x 2 x 30 cm and then conditioned at 25 C and 65 % relative humidity for 3 weeks. Heat treatment was than applied to the wood samples at four different temperatures (130C, 150 C, 180C, 200 C ) and three different durations (2, 6, 10 h) under atmospheric pressure. MOE for control and the heat treated samples were recorded at Universal Test Machine. The results showed that MOE of the wood depended to a considerable extent on the heat treatment conditions, decreasing with increasing temperature and duration of the heating.
S Yildiz, G Çolakoglu, Ü C Yildiz, E D Gezer, A Temiz


Evaluation of the natural durability and ultrasonic method for decay detection of some european hardwood and softwood species
2004 - IRG/WP 04-10537
This paper presents the first part of an investigation on the natural durability of mixed plywood made of durable and non durable plies from the following selected timbers : Cedrus atlantica, Cupressus sempervirens, Castanea sativa, Populus sp. I 214 and Fagus sylvatica. In order to carry out this study, the natural durability of the massive wood used to manufacture the plywood panels was assessed towards wood both white and brown rots (Coriolus versicolor and Coniophora puteana respectively) according to the guidance of the EN 350-1 standard. The sampling was done by taking into account the axial and radial position of the wood samples (sapwood, inner heartwood, outer heartwood) into the log, and sapwood was separated from heartwood when possible. Moreover, the ultrasound velocity was evaluated on these wood samples before and after fungal degradation. On the other hand, the density and the longitudinal modulus of elasticity of the timbers used were measured. In terms of natural durability, the results obtained showed that some differences were noticed between the sapwoods tested, but all of them were considered as non durable. Poplar and beech were shown non durable, on the contrary of chestnut, cypress and cedar heartwood that were very durable. A significant decrease of ultrasound velocity was shown when the decay and the mass loss were considerable. It appeared also the response of the ultrasound velocity was different from brown and white rot decay. Nevertheless, ultrasound velocity measurement was an efficient non-destructive method to evaluate biological decay. The natural durability, as well as the physical and mechanical properties evaluated on massive wood are of interest in order to predict the properties of the plywood that will be manufactured from these studied timbers. These results could be helpful to determine the influence of percentage and pattern of the different plies within the plywood panel, ply thickness and glue lines on the natural durability of plywood.
F Faraji, M-F Thévenon, B Thibaut


Application of non-destructive techniques (durometric and ultrasonic) to evaluate the degradation of woods in service by Gloeophyllum trabeum
2001 - IRG/WP 01-20220
In order to establish the degree of degradation of wood used in construction, it is necessary to employ non-destructive methods (ultrasonic, durometric, densitometric). In this study, ultrasonic and Pilodyn durometric techniques have been applied to try to establish parameters of relationship between the values obtained by both, for their immediate application to wood in service. As a method of reference, the traditional gravimetric technique of percentage of weight loss was used. Two species of pine (P. pinaster and P. contorta), widely used as construction wood in Spain, were assayed. They were subjected to an attack of Gloeophyllum trabeum, a brown rot fungus. Data were collected at 0, 2, 4, and 6 months of incubation. While the ultrasonic technique allowed us to evaluate the degree of alteration, the determination of the hardness of the wood by Pilodyn durometry proved to be excessively aggressive applied to woods that were highly degraded, although it could be used in incipient processes of rot.
M T De Troya, L Palaia, A Navarrete, V Galvañ, R Molina, A Guijarro, J Camacho


Bending properties of wood after its decay with Coniophora puteana and subsequent modification with selected chemicals
1999 - IRG/WP 99-40146
Mechanical properties of wood are often decreased due to decay processes caused by biotic and/or abiotic factors. Damaged wooden elements (e.g. historical structures) can be reinforced by more methods, including their modification with convenient chemicals. This paper presents influences of selected chemicals on basic bending properties (modulus of elasticity - MOE, modulus of rupture - MOR) of sound and decayed wood. Norway spruce (Picea abies L. Karst.) and European beech (Fagus sylvatica L.) samples 8.5 x 8.5 x 120 mm (RxTxL) were deteriorated with the brown-rot fungus Coniophora puteana in laboratory conditions in the interval from 2 to 10 weeks. These rot samples as well as the sound ones were subsequently modified with 5 different chemicals (shellac, epoxy resin, melamineformaldehyde resin, polybutylmethacrylate, or polyethyleneglycol) using pressure impregnation technique (p = 0.8 MPa, t = 6 h). The MOE were evaluated continually for each sample in its sound, rot and modified state (or in sound and modified state), while the MOR just for groups of sound and modified samples. An apparently positive effect on the MOE was achieved with the melamineformaldehyde and epoxy resins, while the polybutylmethacrylate and shellac had only a gentle positive effect. The MOR was increased mainly with the epoxy resin. On the other hand, the polyethyleneglycol - PEG 1000 had an apparently negative effect on both bending properties.
L Reinprecht, S Varinska


Study of modulus of rupture, circumference taper, sapwood thickness and CCA treatment of Norwegian origin Pinus sylvestris poles
1994 - IRG/WP 94-20054
Nondestructive strength testing with Pilodyn (6J) of Norwegian Pinus sylvestris poles revealed effective modulus of rupture (MOR) of 54.39 N/mm² at wet conditions after CCA-C treatment and circumference measurement revealed circumference taper of 0.021 m/n. Sapwood thickness or penetration of CCA-C study revealed that 77% poles were with sapwood thickness equivalent to 39.6% of radius of poles and above, 72% poles were with sapwood thickness equivalent to 40% of radius of poles and above and 59% poles were with sapwood thickness equivalent to 44% of radius of poles and above. Noted that 19% poles were within the sapwood thickness range of 39.6 to 40% of radius of poles and 14% poles within the sapwood thickness range of 40 to 44% of radius of poles. Proper selection of poles before and after preservative treatment regarding desired sapwood thickness would eliminate undesirable poles for REB. X-ray spectroscopic analysis revealed mean retention of dry oxides of CCA-C of w/v 20.58 kg/m³ sd 2.53 (w/w 4.28% sd 0.52) in an assay zone of 2.5 to 45 mm. Regular maintenance of chemical balance of individual component of CCA-C before preservative treatment would be more suitable to have balanced retention of individual component of CCA-C.
A K Lahiry, S Begum, G N M Ilias, M A B Fakir, R U Hafiz


Effect of post-treatment drying schedule on the modulus of elasticity of CCA-treated southern pine dimension stock using nondestructive methods
1987 - IRG/WP 3413
This paper describes the results from the nondestructive testing for modulus of elasticity (MOE) of southern pine (Pinus sp.) 2 x 6&apos;s treated with chromated copper arsenate and redried using three commercial kiln schedules. The data indicate that redrying CCA-treated southern pine dimension stock treated to above-ground retentions (4 kg/m³) has no deleterious effect on the MOE, regardless of the kiln schedule employed. These data tend to confirm conclusions of other work with redrying of treated pine which indicate that MOE is not affected by the redrying schedule.
H M Barnes, S Moore


Effect of aqueous polymer treatments on wood properties. Part 2: Mechanical properties
1990 - IRG/WP 3611
Partially air-dried sapwood of sweetgum (Liquidambar styraciflua) and southern pine (Pinus spp.) was treated with either aqueous polyacrylate or aqueous dimethyloldihydroxyethyleneurea (DMDHEU) solutions. Tests for static bending, toughness, and hardness were conducted on matched treated and untreated pieces according to ASTM Standards. Properties of pine were not affected by treatment with the polyacrylate. With sweetgum, the modulus of rupture and modulus of elasticity were reduced, while hardness was improved. For the DMDHEU treatment, reduction in property values for both species was related to curing temperature.
Z Ashaari, H M Barnes, D E Lyon, R C Vasishth, D D Nicholas


Bending strength of heat-treated spruce and pine timber
2002 - IRG/WP 02-40242
Heat-treatment of spruce (Picea abies) and pine (Pinus sylvestris) beams (45 x 145 mm) gave a reduction in bending strength of approximately 50%. The bending stiffness (modulus of elasticity) only decreased by 3.5%. Tests were carried out according to EN 408. Another effect of the heat-treatment was increased variation in bending strength. The 5th percentile value of the bending strength, the so called characteristic value, decreased by 66% for spruce and by 55% for pine after heat-treatment. The study consisted of 200 spruce beams and 200 pine beams of Swedish origin. Half of the material was heat-treated and the other half was used as controls. The heat-treatment was carried out in a steam chamber in Finland at a maximum temperature of 220°C. The level of treatment was assumed suitable for above ground end uses. When storing the material in a climate that was approximately 20°C/65% relative humidity the heat-treated material reached an equilibrium moisture content of 3-3.5%. For the untreated material corresponding figure was 12-12.5%. The dry density for the heat-treated material decreased by approximately 7.5% compared to the untreated material.
C Bengtsson, J Jermer, F Brem


Acoustic technique for assessing decay in preservative treated wood
1998 - IRG/WP 98-20138
This study investigated the suitability of vibration techniques to assess the performance of wood preservatives in ground contact. Small stakes (10 x 5 x 100 mm3) of treated and untreated Scots pine sapwood were exposed to decay in lab-scale terrestrial ecosystems. Tests were conducted using three different soils including a garden compost soil, and soils obtained from a test field and a conifer forest in Sweden. Wood decay was monitored regularly for one year by determining wood mass losses. Also, strength losses were calculated from the dynamic modulus of elasticity (MOE) of sound and exposed wood specimens as determined by vibration measurements. The results of this study show that the MOE-dynamic losses for the different preservatives and environments have a very good correlation with mass losses. The limited efficiency of some preservatives in an aggressive environment (garden compost soil) was observed. The determination of dynamic modulus of elasticity seems to offer a good basis for assessing the performance of wood preservatives in laboratory soil tests.
L Machek, M-L Edlund, R Sierra-Alvarez, H Millitz


Correlation between modulus of elasticity, mass losses and FTIR spectra of copper treated decayed wood
2006 - IRG/WP 06-10580
The composition of copper-based preservatives will change from copper-chromium to copper-ethanolamine, due to environmental demands. The most important drawback of copper-impregnated wood is the presence of tolerant fungal organisms that have developed an ability to degrade such preserved wood. In order to elucidate these processes, specimens (0.5×1.0×15 cm) made of Norway spruce (Picea abies) were vacuum-impregnated with copper-, chromium-, and copper-ethanolamine-based aqueous solutions (cCu=0.5%), and afterwards exposed to copper-sensitive Gloeophyllum trabeum and copper-tolerant Antrodia vaillantii for various times, between one and eight weeks. After incubation, specimens were isolated, and modulus of elasticity (MOE) losses determined using a nondestructive technique. Mass losses, FTIR spectra, and color changes were measured as well. The results showed that there is significant difference between brown rot decay caused by G. trabeum and A. vaillantii. Decay caused by A. vaillantii is more selective than that caused by G. trabeum. Additionally, it was proven that copper effectively protected spruce from G. trabeum, but not completely against A. vaillantii. Decay of copper-impregnated wood by copper-tolerant fungi is similar to decay of control, unimpregnated wood. Whereas decay of copper-impregnated specimens by G. trabeum, was effectively stopped in its initial stage.
M Humar, B Bucar, F Pohleven


The Use of Modulus of Elasticity and Modulus of Rupture to Assess Wood Decay in Laboratory Soil-Bed Test
2006 - IRG/WP 06-20338
The efficacy of wood preservatives were determined in a soil-bed test. Samples of alder wood sapwood (Alnus glutinosa subsp. barbata) (5x10x100 mm) were treated with Solutions of CCA (1 % and 2 %), ACQ-1900 (2 % and 3 %), ACQ-2200 (1 % and 2 %), Tanalith E 3491 (2 % and 2.8 %), Wolmanit CX-8 (% 1 and 2 %). Modulus of Elasticity, modulus of rupture, mass loss and decay rate according to AWPA E7 were determined for specimens exposed in soil bed. Results from this study showed that modulus of elasticity can be used to prediction of early stage of wood decay since it is non destructive method.
A Temiz, Ü C Yildiz


Treatment of Selected Lesser Used Timber Species against Subterranean Termites using Heartwood Extracts from Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum)
2007 - IRG/WP 07-30434
Lesser used timber species represent a valuable material for all-purpose uses but the problem is that most of them are not durable. They have, for this reason, been treated with all manner of chemicals to enhance their natural durability, especially in the tropics. Often, most of these chemicals pose a threat to the environment. Currently, one probable measure of avoiding such a threat to the environment and organisms is to treat non-durable timbers with extracts from other durable species. Some Ghanaian lesser used timber species were impregnated with heartwood extracts of Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum) and exposed in the field to subterranean termites for 4 months. The effect of these extracts in enhancing the durability of these timbers was studied in accordance with EN 252. Some of the parameters considered were visual characteristics, hardness and weight loss after exposure. The results showed some species to be significantly different in durability between control samples and their treated counterparts (after 4 months) and not in others (after 4 months). Moreover, among the species, durability was high in Pertersianthus macrocarpus while the others followed in the following order: Albizia ferruginea = Blighia sapida = Sterculia rhinopetala > Amphimas pterocarpoides > Sterculia oblonga = Cola gigantean = Antiaris Toxicaria > Canarium schweinfurthii.
A Asamoah, C Antwi-Boasiako


Treatment of Selected Lesser Used Timber Species against Subterranean Termites using Heartwood Extracts from Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum)
2008 - IRG/WP 08-30476
Lesser used timber species represent a valuable material for all-purpose uses. However, most of them are not durable. They are, for effective utilization, often treated with all manner of toxic synthetic substances to enhance their natural durability, especially in the tropics where conditions favour their deterioration. Most of these toxic synthetic substances often pose a threat to the environment. Currently, one probable measure is to treat low durability timbers with extracts from highly durable ones. Heartwood water extracts of Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum) were impregnated into ten Ghanaian LUTS and exposed in the field to the ground for 8 months in accordance with European Norm 252. Visual durability ratings, hardness and mass losses were measured in assessing their field performance. Teak extract did less harm or conferred better resistance on LUTS in more instances than Dahoma extract did. The enhanced durability of LUTS was ranked as follows: Albizia ferruginea > Pertersianthus macrocarpus > Blighia sapida > Sterculia rhinopetala > Amphimas pterocarpoides > Cola gigantean > Celtis zenkeri > Sterculia oblonga > Antiaris Toxicaria > Canarium schweinfurthii. Though extracts showed reduced efficacy with time, indications were that extracts from the heartwood of tropical timber species as that of Teak could be employed to preserve their low durability counterparts. Attempts at fixing extracts permanently in timber should be made. The use of natural organic preservatives is promising if it will be deeply researched.
A Asamoah, C Antwi-Boasiako, K Frimpong-Mensah


Surface Characteristics of Southern pine treated with Eastern red cedar oil
2008 - IRG/WP 08-40393
Treatment of wood with various chemicals play an important role on their surface characteristics including as roughness and hardness for further processing such as finishing and machining. The objective of this study is to evaluate surface roughness of Southern pine (Pinus taeda L.) treated with oil extracted from eastern redcedar (Juniperus viginiana L.). Both tangential and radial surfaces of pine samples were treated two non-pressure methods, namely brushing and cold soaking in the oil. Surface quality of the samples were determined using a stylus technique at the end of each type of treatment. Three roughness parameters, average roughness (Ra), mean peak-to-valley height (Rz), and maximum roughness (Rmax) were used for the quantification of treated surface of the samples. Janka hardness method was also employed to evaluate if there was any effect of treatment on hardness of the samples. Average Ra values of 5.42 µm and 3.67 µm were found for tangential and radial surfaces of 24 hrs soaked samples, respectively. Roughness parameters taken from the surface of control and treated samples did not show any significant difference from each other at 95% confidence level. Average Janka hardness value of radial samples was 2.5 times higher than that of tangential. However, hardness values of control and treated samples also did not show significant difference from each other at above confidence level. Based on the findings of this preliminary study eastern redcedar oil could be considered as alternative treatment chemical for wood products without having any adverse effect on their surface roughness and hardness.
S Hiziroglu


Effects of CCB on wood strength of Eastern spruce (Picea orientalis L.)
2008 - IRG/WP 08-40416
The effects of CCB (chromate copper boron) on the static bending properties of Eastern spruce (Picea orientalis L.) based on MOE (modulus of elasticity) and MOR (modulus of rupture) were evaluated after full-cell vacuum/pressure treatment using a 3.0 % concentration followed by kiln-drying at 15 and 30 % moisture contents with heating the preservative at 30 and 40 ºC. The results showed that MOE and MOR of Eastern spruce affected by the combinations of the level of moisture content of wood and heating temperature of CCB. Provided that heating the solution of CCB caused a greater absorption at 30 ºC but it was lower than that of unheated controls at 40 ºC. The fluid uptake was found to be higher when the samples were dry with moisture of 15 %. The results also showed that the mechanical properties of Eastern spruce affected by the heating temperature of CCB and the moisture content of wood. It was indicated that both MOE and MOR were significantly lower after the treatment process with moisture of 30 % and heated at 40 ºC.
I Usta, M Hale


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