Wood preservation may play an important role in protecting tropical rain forest. Basically, it can reduce pressure on natural resources by increasing wood durability. Field tests are conducted to simulate final use of woods under different environmental conditions. Visual analysis, non destructive testing, and non destructive evaluation techniques were applied to assess wood resistance and chemical preservative efficiency. In Brazil visual analysis is frequently applied in field tests while NDE (Non Destructive Evaluation) techniques have been very little used. We assessed the sound level of treated and non treated wooden fence posts after 15 years in field tests using stress wave and visual analysis techniques. We studied the following wood species: Eucalyptus saligna, Eucalyptus grandis, Pinus elliottii and Sclerolobium paniculatum. Additionally, two non-vacuum/pressure and one vacuum/pressure methods were used to impregnate the fence posts. Creosote, CCA, a mixture of creosote and used motor oil, and a formulation based on fluor chrome arsenate phenol were the chemicals applied. For each wood specie/chemical a combination of 10 samples was treated and other 10 samples for each wood species were used as control. The visual analysis and non destructive evaluation techniques were conducted according to the criteria proposed by the IUFRO. The stress wave timer Metriguard model 239A equipment was also used. These research results showed that the non-destructive analysis method using the stress wave timer device was an efficient alternative to rapidly measure sound level of the wooden fence posts in field test. The average velocity of wave propagation acquired by the stress wave timer was lower in decayed woods compared to sound ones. Also the average velocity of the wave propagation through the buried portion was lower than through the above ground portion of the wooden fence posts. The visual analysis and stress wave timer showed a good relationship as alternative approach to assess sound level of the fence posts in field test.

Download document (509 kb)
free for the members of IRG. Available if purchased.

Purchase this document