Durability of horn beam (Carpinus betulus) wood in natural state and treated with chromated copper arsenate against Coriolus Versicolor

In this study, the influence of the fungus Coriolus versicolor on the durability of horn beam (carpinus betulus) in natural state and treated with chromated copper arsenate (CCA) was evaluated. CCA is a kind of water borne preservative that was used to treat specimens under vacuum and pressure (Bethel procedure) with amount of 3.5 & 1.5 percent on the basis of oven dry wood. Specimens were contaminated with the cultured fungus for eight weeks in incubator. After this period, weight reduction, compressive strength (parallel to grain) and hardness of specimens were measured. Weight reduction of treated samples with 3.5 & 1.5 percent CCA were 1.68 and 1.73 percent respectively. Weight reduction of control samples were much higher (22.87 percent) than treated ones. There was no significant difference between the Compressive strength (parallel to grain) of treated and control samples in the absence of the fungus but in the case of the samples affected by the fungus there were significant differences. Compressive strength (parallel to grain) of treated samples with 3.5 & 1.5 percent of CCA were 64.33 and 60.10 (Mpa) respectively but Compressive strength (parallel to grain) of control samples were much lower (38.44 Mpa) than treated samples. There was no significant difference between the hardness of treated and control samples without effect of fungus. On the other hand, the hardness of treated samples was slightly more than control samples, but this difference was not significant in 5 percent level. The hardness of treated and control samples with the effect of fungus have significant difference. Hardness of treated samples with 3.5 & 1.5 percent of CCA were 5788(N) and 5799(N) respectively. However hardness of control samples were much lower (3139N) than treated samples. Eventually CCA (Tanalith c) increased the durability of horn beam (Carpinus betulus) wood from nondurable level to a durable level.