Differences of Physical, Mechanical and Chemical Properties of Korean Red Pine(Pinus densiflora) Between Old and New Wood

소나무 고목재와 건전재의 물리, 기계, 화학적 특성 차이

  • Shim, Kug-Bo (Div. of Wood Engineering, Dept. of Forest Products at Korea Forest Research Institute) ;
  • Lee, Do-Sik (Div. of Wood Engineering, Dept. of Forest Products at Korea Forest Research Institute) ;
  • Park, Byung-Soo (Div. of Wood Engineering, Dept. of Forest Products at Korea Forest Research Institute) ;
  • Cho, Sung-Taig (Div. of Wood Engineering, Dept. of Forest Products at Korea Forest Research Institute) ;
  • Kim, Kwang-Mo (Div. of Wood Engineering, Dept. of Forest Products at Korea Forest Research Institute) ;
  • Yeo, Hwan-Myeong (Dept. of Forest Science, College of Agriculture & Life Sciences, Seoul National University)
  • 심국보 (국립산림과학원 임산공학부 재료성능과) ;
  • 이도식 (국립산림과학원 임산공학부 재료성능과) ;
  • 박병수 (국립산림과학원 임산공학부 재료성능과) ;
  • 조성택 (국립산림과학원 임산공학부 재료성능과) ;
  • 김광모 (국립산림과학원 임산공학부 재료성능과) ;
  • 여환명 (서울대학교 농업생명과학대학 산림과학부)
  • Published : 2006.12.30

Abstract

The physical, mechanical and chemical properties of old and new Korean red pine (Pinus densiflora) were analyzed. The old woods were from dismantled timbers of Bonjungsa temple. The crystallized resin in the latewood was observed by microscopic analysis. Also, reduction of specific gravity, occurrence of microscopic cleavage of tracheid was observed in the old wood. The angle of microscopic cleavage of tracheid is estimated with the same angle of micro-fibril angle of 52 layer. The bending, compression and shear strength of old world were decreased about 35-27% than those of new wood. Dynamic modulus of elasticity measured by ultrasonic nondestructive test has the tendency of reducing by the time elapse of the wood usage. Therefore, deterioration of wood could be measured by reduction of specific gravity and dynamic MOE. The static MOE and mechanical properties of old wood could be predictable by measuring dynamic MOE in the longitudinal direction. Extractives of the old wood in 1-% NaOH solution are larger quantity than new wood. Therefore the decay of the wood could be evaluated by analyzing the chemical compound, especially 1-% NaOH solution. The results of this research could be used for understanding and prediction of the changing properties with elapsing time of wood.