The purpose of this study was to present evidence for the effects of concentration and temperature of solutions of water-borne preservatives (chromated copper arsenate, CCA and chromated copper boron, CCB) on the static bending properties (modulus of elasticity, MOE and modulus of rupture, MOR) of Turkish fir (Abies bornmulleriana Mattf.). Wood samples were mechanically tested after a mild full cell preservative treatment with 2.5 and 3.0% CCA and CCB solutions heated to 30 and 40 °C.Untreated controls were included for comparison.The experimental data indicated that heating the solutions of both CCA and CCB caused a greater shift in the fluid uptake, i.e. it increased with temperature up to 30 ºC, but at 40 ºC it was lower than that of unheated controls. In absolute terms, the fluid uptake of either preservative solutions was higher particularly in lower concentrations. CCB treatment had a greater fluid uptake for all cases. Results also showed that the effects of increasing concentration and temperature of both water-borne preservatives on MOE and MOR were very highly significant, while these strength properties were a significantly lower after the wood treatment with concentration of 3.0 % and heated at 40 ºC. Both MOE and MOR decreased even more by the treatment of CCB. It was therefore concluded that the strength properties of Turkish fir based on MOE and MOR were affected to a small extent by the full-cell vacuum/pressure wood treatment by using CCA and CCB with the concentrations of 2.5 and 3.0 % heated at 30 and 40 ºC. The worst case was 3.0% CCB treatment at 40 °C which resulted in a 5.0% reduction in MOE and a 5.2% reduction in MOR.

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