Progress 08/01/99 to 07/31/05
Outputs
During the reporting period from 1/01/2005 until 5/31/2005 work continued concerning an evaluation of methods used to determine the specific gravity of wood increment cores. The focus of this work was on the use of the maximum moisture content technique to determine specific gravity of 5mm diameter southern pine wood increment cores. During the reporting period work also continued on the analysis of strength-wood property relationships in finger-jointed southern pine and on the variation of juvenile and mature wood specific gravities within a southern pine tree stem. Both of these studies terminated on 5/31/2005 when Dr. Dougal was not awarded tenure and resigned his position.
Impacts
Information obtained concerning the methods used to determine specific gravity from wood increment cores may assist those using these measurements to improve accuracy of specific gravity determinations and thereby potentially improve the value of this property for wood quality assessments. Information obtained on the finger-joint project concerning strength-wood property relationships of finger-jointed southern pine may be of use to individuals involved in raw material quality control aspects. It is anticipated that the within-tree sampling specific gravity information obtained from this research may assist forest growers with their resource assessment needs especially in situations where destructive samples are obtained.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
During the reporting period work was conducted concerning an evaluation of methods used to determine the specific gravity of wood increment cores. The focus of this work was on the use of the maximum moisture content technique to determine specific gravity of 5 mm diameter southern pine wood increment cores. Based on earlier measurements involving unextracted cores, differences were observed between specific gravity determined gravimetrically and specific gravity determined using the maximum moisture content technique. While some differences in specific gravity based on unextracted cores were expected between the two techniques, the extent and magnitude of the differences observed were greater than expected. Based on previously published information concerning these methods, the mathematical relationship between techniques is being examined. Further investigation based on these fundamental aspects is under consideration with the intent of identifying if a potential
correction factor or factors can be developed. If so, these factors may be applied to existing specific gravity measurements to test their effectiveness and further experimental work may be conducted based on extracted cores if needed. During the reporting period work also continued on the analysis of strength-wood property relationships in finger-jointed southern pine and on the variation of juvenile and mature wood specific gravities within a southern pine tree stem.
Impacts
Information obtained concerning the methods used to determine specific gravity from wood increment cores may assist those using these measurements to improve accuracy of specific gravity determinations and thereby potentially improve the value of this property for wood quality assessments. Information obtained on the finger-joint project concerning strength-wood property relationships of finger-jointed southern pine may be of use to individuals involved in raw material quality control aspects. It is anticipated that the within-tree sampling specific gravity information obtained from this research may assist forest growers with their resource assessment needs especially in situations where destructive samples are obtained.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
During the reporting period work continued on the assessment of wood properties of finger-jointed southern pine. Work concerning the variation of wood moisture content within finger-jointed specimens following a durability cycle was completed. In this study moisture content variation was examined in four batches of commercially manufactured structural finger-jointed southern pine. Variation in moisture content between the two pieces of wood within finger-jointed specimens was larger in the three batches that gained moisture as a result of the durability cycle. Less variation in moisture content between the two pieces of wood within finger-jointed specimens was found in the one batch that lost moisture as a result of the durability cycle. Methods that account for this moisture content variation between wood pieces within finger-jointed specimens may need to be considered in existing standards that specify durability cycles. Also, further work that examines the effect
of within-finger-joint specimen moisture content variation on subsequent strength tests and glueline delamination measurements may be warranted. Work also continued on other wood property aspects of this project. Based on 11 batches of commercially manufactured finger-jointed southern pine, a mean specific gravity of 0.550 and a mean rings per inch of 6.49 were found. Differences of 0.062 in specific gravity and 2.49 in rings per inch were found, on average, between the two pieces of wood within a finger-jointed specimen. Maximum differences of 0.315 and 13.19 were found for the specific gravity and rings per inch properties respectively. Initial analyses were completed that examined strength-wood property relationships in finger-jointed southern pine. Wood failure measurements were made on broken specimens and strength-wood property relationships examined using data from specimens separated into wood failure subgroups. The highest coefficients of determination were found for
specimens exhibiting fractures where the failure appeared to occur equally between the wood fingers of the two pieces of wood originally jointed together. During the reporting period work also continued on the project concerned with sampling for wood specific gravity at twenty percent of total tree height in southern pine. Work focused on a species-specific analysis of specific gravity results for a subset of 113 loblolly and slash pine trees. Strong relationships were found between specific gravity at the twenty percent height and tree specific gravity for both species. Approximately an additional ten to twenty percent of variation was accounted for by sampling at the twenty percent height relative to breast height in both species. Further analyses are being done that aim to examine relationships based on specific gravities of juvenile and mature wood segments.
Impacts
Information obtained on the finger-joint project concerning moisture content variation within finger-jointed specimens may be of use to individuals involved in the revision and use of finger-joint standards. It is anticipated that the within-tree sampling specific gravity information obtained from this research may assist forest growers with their resource assessment needs especially in situations where destructive samples are obtained.
Publications
- Knowles, Christopher David. 2003. Wood properties of finger-jointed southern pine. Master of Science in Forestry thesis, Stephen F. Austin State University, Nacogdoches, Texas. 157 p.
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Progress 01/01/02 to 12/31/02
Outputs
During the reporting period work continued on the assessment of wood properties of finger-jointed southern yellow pine. Mechanical bending and tension tests were conducted on 240 southern pine finger-jointed test specimens during the reporting period and wood quality measurements were made on each half of each test specimen following procedures described in an earlier CRIS research report on this project. One aspect of this research has been concerned with the effect of a durability cycle on the distribution of moisture between the two halves of a finger-jointed specimen. Preliminary moisture content results based on an examination of 148 matched test specimens appear to indicate that following the durability cycle test specimens have a more unequal distribution of moisture between the two halves of the finger-jointed specimen. This effect appears to be accentuated in specimens that have not been dried sufficiently following the soaking part of the durability cycle.
In addition to this aspect of the research on finger-jointed southern pine, analyses are continuing on the characterization of properties of the wood in finger-jointed stock and on the relationship between these properties and mechanical strength properties. During the reporting period work also continued on the project concerned with sampling for wood specific gravity at twenty percent of total tree height in loblolly and slash pine. In cooperation with Temple-Inland Corporation, wood from 113 trees located at 20 sites in east Texas and western Louisiana was examined. Tree specific gravity was obtained from measurements made on wood discs removed at 5-foot intervals up the stem. Specific gravities at 20 percent of total tree height and at breast height were obtained from measurements made on wood strips removed at these heights. Based on either one pith-to-bark wood strip or one bark-to-bark strip a strong relationship was found between specific gravity at the twenty percent height
and tree specific gravity. Preliminary results would appear to indicate a reduced variation at the 20 percent height compared to breast height. These results may have applications in situations where trees are sampled destructively in the field.
Impacts
It is anticipated that information obtained from this research may assist forest growers with their resource assessment needs especially in situations where destructive samples are obtained. Information obtained on the finger-joint project may assist manufacturers and personnel involved in quality control and testing in their understanding of incoming raw material quality as related to product testing and end product performance.
Publications
- Jones, Paul David. 2002. Assessment of basic specific gravity of southern yellow pine trees sampled at twenty percent of total tree height. Master of Science in Forestry thesis, Stephen F. Austin State University, Nacogdoches, Texas. 106 p.
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Progress 01/01/01 to 12/31/01
Outputs
During the reporting period work continued on the project entitled `Genetic, silvicultural and environmental effects on growth and wood quality of southern pines'. Mechanical bending tests were conducted on an additional 120 finger jointed southern pine specimens. Wood quality measurements were made on each half of the test specimens as described in the previous CRIS research report. An analysis of a subset of bending specimens was conducted during the reporting period. The average specific gravity at time of test was found to be 0.485 with values ranging from 0.388 to 0.661 (measured on each half of the bending specimens). The average ring width was found to be 0.18 inch with values ranging from 0.06 to 0.40 inch. Analyses are continuing and are aimed at getting a better understanding of how the mechanical properties of finger jointed stock are influenced by the varying wood quality of each of the two pieces of wood joined together. In related research on southern
pine, work continued on the use of increment cores to assess wood physical and mechanical properties. In cooperation with Temple-Inland Corporation 138 trees located on 23 sites were felled and wood discs removed every five feet up the stem during the reporting period. Prior to felling increment cores were obtained at breast height and the basic specific gravity of each core was determined in the laboratory. Pith to bark wood strips were also obtained at breast height and twenty percent of total tree height. At present, work continues on the determination of wood properties of the discs and this information will be used to determine whole tree wood properties. An initial aim of this work is to examine the relationships between whole tree wood properties and those determined at breast height and twenty percent of total tree height.
Impacts
It is anticipated that information obtained from this research may assist forest growers with their resource assessment needs and may also assist forest products manufacturers in their understanding of incoming raw material quality as related to end product performance.
Publications
- No publications reported this period
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Progress 01/01/00 to 12/31/00
Outputs
During the reporting period work continued on the project entitled 'Genetic, silvicultural and environmental effects on growth and wood quality of southern pines'. Mechanical bending tests were conducted on about 500 fingerjointed southern pine specimens. One and a half-inch by one and a half-inch wood specimens were used representing a wide range of growth rates and age. Wood quality measurements were made in order to determine the specific gravity and moisture content at time of the test. Additionally, oven-dry specific gravity and ring width measurements were made. All of these wood properties were determined on small wood blocks from each of the two wood pieces comprising the fingerjointed bending test specimens. Analysis is currently underway to examine the impact of the wood properties of each of the two wood pieces on the final bending strength of the fingerjointed specimen. This approach is being taken in order to gain a better understanding of how the
mechanical properties of fingerjointed stock are influenced by the varying wood quality of each of the two pieces of wood joined together. In related work on southern pine, initial investigations have begun on the methodologies concerned with the use of increment cores to assess wood physical and mechanical properties. Information obtained from this work may assist forest growers with their resource assessment needs and may also assist forest products manufacturers in their understanding of incoming raw material quality as related to end product performance.
Impacts
It is anticipated that findings from these studies may result in a better understanding of incoming raw material quality and in improved processing and utilization of wood products.
Publications
- No publications reported this period
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Progress 08/01/99 to 12/31/99
Outputs
This project (TEXY111) being conducted at Stephen F. Austin State University was started on August 1, 1999. An examination of the morphological and physical properties of wood from fast grown southern pine trees has been initiated. Wood specimens of varying growth rates have been identified and properties including ring width, percent latewood, and specific gravity are being examined. A further aspect of this work is to assess the relationship between wood properties and the strength and quality of fingerjointed wood. Current efforts are focusing on the identification and assessment of appropriate methodologies to examine fingerjointed stock. Information obtained from this work may assist secondary forest products processors to better understand the impact of varying wood properties on the performance of fingerjointed products.
Impacts
It is anticipated that findings from this project may result in improved processing and utilization of wood products.
Publications
- No publications reported this period
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