木材の老化に関する研究 : (第 V 報)古材の伸縮性

概要

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In the present stndy the shrinkage and swelling of old timbers were observed in comparison with new timbers to secure the change of properties of wood after the lapse of so many years. The samples were selected from construction timbers of old temples which were built of Hinoki (Chamaecyparis obtusa ENDLICHER). These timbers have elapsed respectively, A : about one thousand and three houndred years, B : about nine houndred years, C : about seven houndred years, D : about three houndred and fifty years, E : about thee houndred years, F : new timbers six years. The experiment was carried out in the thermostat keeped at 45℃. The osillations of oven-dry to satulated moisture condition were repeated 22 times. The test pieces being carefully selected for straightness of grain and their size were 30×30×1.2mm. The marks were drawn 25mm length on tangential surfaces, and shrinkage were measured when the pieces had become equilibrium states. The test yields the bollowing resuls. (1) The courses of shinkage and swelling when the oscillations of oven-dry to satulated atmosphere were repeated to wood are shown in fig. 7. (2) The changes of percentage of shrinkage after the lapse of so many years are shomm in fig. 9.
京都府立大学の論文
1953-09-01