@inproceedings{83d321f4af21423da89ac1dab57e5ea5,
title = "Comparison of methods of strength classification of (tropical) hardwood timber",
abstract = "The number of tropical hardwoods being used in structural timber over the last years is increasing. This is due to the fact that tropical hardwoods from sustainable managed forests are coming on the market in growing numbers and quantities. Tropical hardwoods are wanted for there high durability and high strength. The growing number of hardwood species gives problems in deriving reliable mechanical strength properties, because extensive testing of all species is not a realistic economical option. In different parts of the world there are different methods to derive the strength properties for timber. They are either based on tests on small clear samples or on tests on timber of structural sizes. Both methods have there advantages and disadvantages. Tests on small clear samples can be performed on a larger number of test specimens. The question is how much they are related to the end use of structural sizes. For the tests on structural sizes the amount of tests economically possible is a limiting factor. In the present situation, both methods are being used for classification of visually graded timber. In this paper both methods are compared for two full size and two small size samples of cumaru (dypterix odorata) coming from two different sources. The result was that the 5-percentile bending strength of the full size specimen can not precisely be predicted by using small clear specimen. Using correlations between the full size and small size samples of both sources a size factor can be determined. Together with a factor taking into account the presence of weak specimen in full size samples, the 5-percentile value of the full size specimen can be more accurately predicted out of the parametric 5-percentile value of the small size specimen (both clears and non-clears).",
keywords = "Full size specimen, Small specimen, Strength properties, Tropical hardwood",
author = "Geert Ravenshorst and {Van De Kuilen}, {Jan Willem}",
year = "2010",
language = "English",
isbn = "9781622761753",
series = "11th World Conference on Timber Engineering 2010, WCTE 2010",
pages = "1004--1012",
booktitle = "11th World Conference on Timber Engineering 2010, WCTE 2010",
note = "11th World Conference on Timber Engineering 2010, WCTE 2010 ; Conference date: 20-06-2010 Through 24-06-2010",
}