| Research Abstract |
This investigation were carried on to a few fundamental properties of hardwoods of 11 species grown in Amamiooshima and Kagoshima city. Three piecies of the stem, fixed at breast-height 30-40 cm long in diameter were adopted as the samples to be used for ascertaining some physical and mechanical properties as well as the respective specific gravities. The specimen were obtained in the stem measuring from 0.2m to 4m in heights above the ground, along the stem diameter, through pith from a sapwood to another.
In the holding, the following physical and mechanical properties were examined.
1. Physical properties ( a specific gravity,moisture content in green condition, and shrinkage along the tangential, radia and longitudinal directions.)
2. Mechanical properties ( bending test,compressive test,impact-bending test, shearing test and cleavage test.)
3. A testing of adhesive ( uria resin adhesive,polyvinyl acetate resin adhesive, polyurethane resin adhesive and resorcinol resin adhesive ).
4. Th
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e trial construction of dr ing shedule ( four species ).
The experimental results obtained about the phisical, mechanical and adhesive properties, and other properties are summerized as folloes;
1. The specific gravity and amoisture content in green ranged 0.44-0.98, from 52 % to 91 %.
2. The shrinkage from green to oven-dry-condition was was 6.83%-12.7%,3.81-5.18% along and radial direction, in respective species. On the oter hand, average shrinkage per 1% moisture-content was 0.22%-0.29%,and 0.16%-0.18% inrespective species.
3. As described in the previous papers, based on the discussionsmade on the variations in the respective mechanical properties which were observable and decreasing along the radial direction from pith to bark, an existence of the five typed variations along the stem-radius from pith to bark was ascertained.
4. Based on the statistical discussions about the specific gravities and mechanical properties under the air conditions, a relativity was confirmed between the specific gravity and mechanical properties. Less
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