Abstract
Previously, we built self-buildable and low cost greenhouses using bamboo called “Kumano Bamboo Greenhouses (BGHs)” experimentally in Kumano city, Mie prefecture. We reported cost for materials could be lower than steelpipe house by using bamboo, however construction work needs longer time than that of steel-pipe house. Moreover, Ito et al. (2010) noted cost of procurement for bamboo using materials as unused natural resources was needed. The objective of this study was to decrease time for construction work improving BGH structure and to decrease procurement cost for material bamboo cooperating with administrative organization.
Materials costs for both BGH No. 3 and BGH No. 4 were lower than that of BGH No.2. This is approximately half that of a steel-pipe house. BGH No. 3 and BGH No. 4 could be built in 138.4 and 77.2 hours respectively, time for construction work could decrease by that in BGH No.2 needed 264 hours. The calculation of structural strength was diffi cult because of the variability of dryness and degradation of bamboo materials. However, critical damages have not been observed in either BGHs during the 20 months post-construction. In BGH No. 4, horizontal oscillation by side wind was observed.
From these results, it is found that material cost included procurement of bamboo for BGHs produced in this study (BGH No. 3 and BGH No. 4) and time for construction work could be decreased than that of BGH No. 2. These BGHs can be self-built at a small-scale, irregular-shaped farmland, so they may be useful for agriculture promotion in mountain villages. Moreover, cooperation with maintenance of bamboo grove could not decrease cost for BGH building but also help to prevent animal damage and conserve the traditional landscape of farming.
