Decreasing of cca-a retention in pinus stakes after 21 years of exposure in a field teste. / Variações na retenção de CCA-A em estacas de Pinus após 21 anos de exposição em campo de apodrecimento.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

The durability of treated wood in direct ground contact is mainly determined, by the concentration of preservative in wood, usually defined as retention. Among the products used to preserve wood, specialized literature aggress about CCA (chromated copper arsenate) as one of the most efficients, with citations of durability above 40 years. However, product loss along exposure time is also noticed, which could compromise its efficiency. This research has as objective, to quantify the current retention of CCA type A in Pinus stakes, after 21 years of exposure in field test, trying to relate the level of retention to the possible product loss and to wood durability . The material on trial was collected from a stake field test (IUFRO Standard); in order to quantify the current retention through spectroscopy atomic absorption technique and to compare the results with the initial retention. It was possible to prove the CCA-A loss in the treated wood, which is directly related to the level of initial retention. From individual preservative components, copper (CuO), showed the biggest loss, while chromium (CrO3) showed the lesser one. As a result, the remanaing CCA-A in the lumber turned unbalanced. However, the reduction observed in the retention of the CCA-A, until this moment, did not affect the durability of preserved wood.

ASSUNTO(S)

preservação da madeira pinheiro pinus sp wood (treating) wood preservation madeira (tratamento)

ACESSO AO ARTIGO

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