Comparison of natural durability of wood by stake tests followed by survival analysis

Journal of Wood Science

Yuji Imamura¹  Wakako Ohmura²  Toshikazu Kakutani³  Ikuo Momohara⁴  Haruko Sakai⁵  Tokio Sekizawa⁶  Hiroshi Kurisaki⁷ 

[1] Architectural Research Association;Forestry and Forest Products Research Institute;Kanematsu Sustec Corporation;Kansai Research Center, Forestry and Forest Products Research Institute;Nara Forest Research Institute;The Japan Wood Preservers Industry Association;Toyama Forest Products Research Institute;

关键词: Wood;    Durability;    Stake test;    Field test;    Survival analysis;    Service life;   

DOI  :  10.1186/s10086-021-01976-6

来源: DOAJ

【 摘 要 】

Abstract The conventional stake test is widely used to evaluate wood durability. The test monitors the deterioration level observed on stakes partially inserted into the ground. The test results are conventionally expressed as the relationship between the mean deterioration level and exposure periods. Durability is compared between the stake groups based on the test results; however, there is no scientific basis for the comparison. To include a scientific basis to the conventional stake test, we applied survival analysis to it. Four stake groups were subjected to deterioration at three sites for 7 years. The deterioration levels were monitored according to the conventional procedure, and survival analysis was applied to the monitored data. The Kaplan–Meier curves plotting the survival probabilities against the exposure periods indicated that the durability of the test stakes of Japanese cedar heartwood is higher than those of Japanese cedar sapwood. However, it was also demonstrated that the durability ratio between Japanese cedar heartwood and sapwood was strongly dependent on the test sites. It was also revealed that the durability of the heartwood portion did not differ significantly among Japanese cedar, Japanese cypress, and Japanese larch. These results were verified using the modified Gehan–Wilcoxon test.

【 授权许可】

Unknown