文献类型：会议论文

英文题名：Bending properties and visual grade of Chinese fir plantation dimension lumber: Effect of pith and growth ring width

作者：Jiang, Jinghui[1] Lu, Jianxiong[1] Ren, Haiqing[1] Chao, Long[1]

第一作者：江京辉

通信作者：Jiang, J.

机构：[1] Research Institute of Wood Industry, Chinese Academy of Forestry, No.2 Dongxiaofu, Xiangshan Road, Haidian District, Beijing, China

会议论文集：11th World Conference on Timber Engineering 2010, WCTE 2010

会议日期：June 20, 2010 - June 24, 2010

会议地点：Trentino, Italy

语种：英文

外文关键词：Bending strength - Grading - Timber

年份：2010

摘要：The dimension lumber of plantation Chinese fir was graded to four different grades as SS, No.l, No.2 and No.3, according to national lumber grades authority (NLGA) standard grading rules for Canadian lumber. At 15% moisture content, bending strength and stiffness were tested according to American Society for Testing and Materials D4761-02a. The results showed that for SS and No.2 grades lumber the MOE and MOR values were significantly different between the lumber with and without pith, but contrary to No.3 lumber. The mean MOE and MOR decreased as growth ring width (GRW) of each graded lumber increased. MOR and MOE of the SS and No.2 grades dimension lumber were very significantly different between GRWth percentile MOR values of those grades lumber were also increased about 7.0%. In addition, the dimension lumber of plantation Chinese fir with pith and GRW ≥6mm should be graded into No.3 grade, and the mean MOE, MOR and 5th percentile MOR values were not affected.