Abstract
Azekura-zukuri style wood structures (hereinafter referred to as azekura-style structures) have been utilized in forest conservation projects in Japan as substitutes for concrete structures. We estimate that making use of thinned and small logs for azekura-style structures has positive impact on circular economy and carbon fixation and contributes to the biodiversity within their areas. In addition, logs compressed and injected with wood preservatives give structures long-time durability.
In this research, we installed three types of azekura-style structures 10 years ago to compare their durability under the same weather condition. One was made of non-treated logs and another was made of injected logs. The other was made of compressed and injected logs.
Through these 10 years, we constantly implemented visual and touch confirmation first to estimate the difference of their extents of biological damage. We also used the resistograph, a power drill-based device to measure the difference of damage.
As a result, non-treated logs posed drastic losses of durability due to decay. Injected logs kept the functions of the structures, but consecutive parts of decay were observed. On the other hand, compressed and injected logs demonstrated almost no particular decay and easily maintained the functions of structures.
Following the outcome, we estimated that the azekura-style structures made of compressed and injected logs would enjoy the longest-time durability.