Evaluation of Decay Resistance for Steam-heat- Treated Wood

The objective of this research was to evaluate the influence of steamheat treatment on the decay resistance of Chinese white poplar and Chinese fir wood against the wood-rotting fungi Gloeophyllum trabeum (Pers.:Fr.) Murrill. The Chinese white poplar and Chinese fir specimens were obtained from Shandong and Hunan provinces, respectively. They were steam-heat-treated at 170, 185, 200, 215, or 230 C with time duration of 1, 2, 3, 4, and 5 hrs in an air-tight chamber that comprised less than 2 per cent oxygen. According to the standard GB/T 13942.192, the decay resistance experiments were completed with the woodrotting fungi G. trabeum on an agar block test with 12-week incubation. The results of steam-heat treatment indicated that, compared to a weight loss of 56% for untreated samples, a weight loss of 45% decreased to just 2% for Chinese white poplar with an increase in temperature from 170 to 230 . No weight loss was observed in the steam-heat-treated China-fir heartwood, sapwood, and untreated sapwood specimens, while only a weight loss of 4.739% in untreated China-fir heartwood specimens was found.