Toshiro Morooka
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Fiksasi Bambu Gombong dan Tali Fixation of Gombong and Tali Bamboos Wahyu Dwianto; Toshiro Morooka; Misato Norimoto
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 2, No 1 (2004): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Masyarakat Peneliti Kayu Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (242.645 KB) | DOI: 10.51850/jitkt.v2i1.319

Abstract

This research describes stress relaxation measurement to understand the fixation mechanism of compressive deformation of water saturated Gombong bamboo (Gigantochloa pseduarundinaceae) and Tali bamboo (Gigantochloa apus). Stress relaxations are measured by compressing the specimens in radial direction to 0.2 strains between 110ºC and 190ºC for various periods of time in electro oil hydraulic testing system equipped with an autoclave, which was heated by high temperatures saturated steam.        The stress approximately disappears in 60min at 170ºC, in 30min at 180ºC, and in 20 min at 190ºC for Gombong bamboo. On the other hand, the fastest release of stress is found for Tali bamboo. The plots of relationship between residual stress and strain recovery of Gombong and Tali bamboos lay on a single curve, respectively. The relationship is similar to that of Sugi wood by heating. However, the weight loss of the two bamboos is extremely higher than that of wood. The fixation is achieved at a weight loss of 20% for Gombong and Tali bamboos. From these results, the fixation mechanism is considerably dominated by the decomposition of hemicelluloses and lignin.
Permanent Fixation of Radially Compressed Bamboo in Dry Condition by Heating and Its Mechanism Bambang Subiyanto; Wahyu Dwianto; Takashi Higashihara; Toshiro Morooka; Misato Norimoto
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 9, No 1 (2011): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Masyarakat Peneliti Kayu Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (303.724 KB) | DOI: 10.51850/jitkt.v9i1.142

Abstract

The stress-strain relationship and stress relaxation of oven-dried bamboo in radial compressed by heating were investigated. The effect of heating temperature and time on the weight loss, residual stress and strain recovery were also examined. The results indicated that the apparent of stress-strain curve (SS-curve) of Indonesian bamboo was different with Mousou bamboo and Sugi wood. The apparent SS-curve of Mousou bamboo was same as general SS-curve of wood under heating. The effect of heating temperature on yield stress of oven-dry bamboo had different results with the Sugi wood. The yield stress of bamboo decreased slightly up to heating temperature of 140 °C, then it was significantly decreased with increasing temperature. The decreasing yield stress of bamboo at heating temperature above 140 °C could be due to degradation or decomposition of existing extractive component and hemicelluloses in bamboo by heating. Time to achieve stress relaxation decreased with increasing heating temperature. The stress relaxation of bamboo was attained faster than that of Sugi wood. Tali bamboo had a fastest to attain stress relaxation than others type of bamboo. The residual stress and strain recovery decreased with decreasing weight loss. The most interesting finding was residual stress of Indonesian bamboo (Gombong and Tali bamboos) was attained zero and stress recovery less than 0.2 when the weight loss at about 4%.Key words: bamboo, permanent fixation, stress-strain.