C بررسي دوام چوب تبريزي در حالتهاي حفاظت شدن با كريوزوت و تاناليت

A Study on Durability of Treated Populus nigra Wood with Creosote and Tanalite C

The influence of fungus (Coriolus versicolor) on durability of sapwood as well as heartwood of black poplar (Populus nigra var.pyramidalis) ʹin either natural state or treated with creosote and tanalite C (Chromate,Copper , Arsenic ) in five concentrations (1,2,3,4 and 5 percent ) by use of Kolleshaleʹs rnethod and according to prEN:113 (1994) standards was studied. A factorial design of randomized blocks was used as statistical plan for the analysis of the results. Specimens were treated employing Bethel procedure after which the samples were contaminated with fungus(Coriolus versicolor) cultured in Kolle on malt extract agar culture. The cultured fungus continued its growth under 25°C temperature, and 15% relative humidity for sixteen weeks. Weight reduction was measured, the results being as follows: weight reduction in samples was observed to be significant. Heartwood weight reduction was observed to be more than sapwood weight reduction.There was a relationship between the type of preservative as well as salt percentage with weight reduction. Salt with different concentrations and the type of preservative exerted a strong influence on durability of the samples and according to standards, undurable control samples were changed into very durable ones. The effect of five different concentrations of salt was shown to be significant in weight reduction. Salt with 3,4 and 5 percent concentrations were placed in one group. Since concentration of 3 percent required less use of chemicals , therefore it most suitable was chosen as the concentration.Weight reductions in treated samples with tanalite C (3 percent concentration) and with creosote (as compared to control samples) were significant at 1% level. of probability. But there was no significant difference observed between treated samples with tanalite C (3 percent) and creosote at this level.