Characteristics of Ten Tropical Hardwoods from Certified Forests in Bolivia Part I Weathering Characteristics and Dimensional Change

Authors

  • R. Sam Williams
  • Regis Miller
  • John Gangstad

Keywords:

Wood properties, weathering, density, growth rate, erosion rate, flat-grain, vertical-grain, durability, natural durability

Abstract

Ten tropical hardwoods from Bolivia were evaluated for weathering performance (erosion rate, dimensional stability, warping, surface checking, and splitting). The wood species were Amburana cearensis (roble), Anadenanthera macrocarpa (curupau), Aspidosperma cylindrocarpon (jichituriqui), Astronium urundeuva (cuchi), Caesalpinia cf. pluviosa (momoqui), Diplotropis purpurea (sucupira), Guibourtia chodatiana (sirari), Phyllostylon rhamnoides (cuta), Schinopsis cf. quebracho-colorado (soto), and Tabebuia spp. (lapacho group) (tajibo or ipe). Eucalyptus marginata (jarrah) from Australia and Tectona grandis (teak), both naturally grown from Burma and plantation-grown from Central America, were included in the study for comparison. The dimensional change for the species from Bolivia, commensurate with a change in relative humidity (RH) from 30% to 90%, varied from about 1.6% and 2.0% (radial and tangential directions) for Amburana cearensis to 2.2% and 4.1% (radial and tangential) for Anadenanthera macrocarpa. The dimensional change for teak was 1.3% and 2.5% (radial and tangential) for the same change in relative humidity. None of the Bolivian species was completely free of warp or surface checks; however, Anadenanthera macrocarpa, Aspidosperma cylindrocarpon, and Schinopsis cf. quebracho-colorado performed almost as well as teak. The erosion rate of several of the wood species was considerably slower than that of teak, and there was little correlation between wood density and erosion rate. Part 2 of this report will include information on the decay resistance (natural durability) of these species.

References

Bhat, K. M. 1998. Properties of fast-grown teak wood: Impact on end-user's requirements. J. Tropical Forest Prod.4(1):1-10.nBlack, J. M., and E. A. Mraz. 1974. Inorganic surface treatments for weather-resistant natural finishes. Res. Pap. FPL 232. USDA Forest Serv., Forest Prod. Lab., Madison, WI. 40 pp.nBurmester, A. 1972. Swelling and swelling anisotropy of wood in various moisture-content ranges. Holz Roh-Werkst.30(10):380-381.nBurmester, A. 1975. Dimensional stabilization of wood. Holz Roh- Werkst.33(9):333-335.nBurmester, A., and W. E. Wille. 1975. Investigations on the dimensional stability of teak. Holz Roh- Workst.33(4):147-150.nChudnoff, M. 1984. Tropical timbers of the world. Agric. Handbk. 607. USDA Forest Service, Washington, DC.nFeist, W. C., and E. A. Mraz. 1978. Comparison of outdoor and accelerated weathering of unprotected softwoods. Forest Prod. J.28(3):38-43.nFlorsheim, S. M. B., and M. Tormazello-Filho. 1996. Variations of cell dimensions in the pith-bark and base-top directions in "aroeira" Myracrodruon urundeuva F.F. & M.F. Allemao (Anacardiaceae). 1. Fibers. Revisto do Instituto Florestal 8(2):153-165.nForestry and Forest Products Research Institute. 1998. Properties of some Papua New Guinea woods relating with manufacturing processes. VI. Wood qualities, physical properties, and decay durability of some West New Britain woods. Bulletin 299. Forestry and Forest Products Research Institute. Working Group on Utilization of Tropical Woods, Japan.nHernández, R. E. 1993. Influence of moisture sorption history on the swelling of sugar maple wood and some tropical hardwoods. Wood Sci. Technol.27(5):337-345.nSell, J., and W. C. Feist. 1986. Role of density in the erosion of wood during weathering. Forest Prod. J.36(3):57-60.nSimatupang, M. H., E. Rosamah, and K. Yamamoto. 1996. Importance of teakwood extractives to wood properties and tree breeding. Pages 235-246 in A. M. A. Rashid et al., eds. Forestry and forest products research: Proc. of the third conference. Vol. 2. October 3-4, 1995. Kepong, Malaysia. Forest Research Institute Malaysia (FRIM), Kuala Lampur, Malaysia.nWang, S. Y. 1981. Studies on the properties of wood deterioration. (6) The reduction in strength properties of some Taiwan species after 4 years' exposure in outdoor environments. Quart. J. Chinese Forestry14(4):29-39. (Reviewed abstract only).nWang, S. Y. 1990. Reduction of mechanical properties of seventeen Taiwan native-wood species subjected to a seven-year exposure in an outdoor environment. Mokuzai Gakkaishi36(1):69-77.nWang, S. Y., C. M. Chiu, and Z. C. Chen. 1980a. Studies on the properties of wood deterioration. (1). The weathering resistance of sixteen different Taiwan native wood species tested by accelerated weathering resistance method. Quart. J. Chinese Forestry12(1):21-39.nWang, S. Y., C. M. Chiu, and Z. C. Chen. 1980b. Studies on the properties of wood deterioration. (2). The decay resistance of eighteen different Taiwan native wood species tested by accelerated decay resistance method. Quart. J. Chinese Forestry13(1):55-93. (Reviewed abstract only).nWilliams, R. S., M. T. Knaebe, J. W. Evans, and W. C. Feist. 2001. Erosion rates of wood during natural weathering: Part 3. Comparison of exposure angle with erosion rate. Wood Fiber Sci.33(1):50-57.n

Downloads

Published

2007-06-05

Issue

Section

Research Contributions