Effects of Fixation Drying Conditions on Fixation Rate and Leachability in CCA-C Treated Red Pine and Southern Pine

The effects of fixation drying conditions on fixation rates and chemical leachability were investigated with CCA-C treated red pine (Pinus koraiensis Sieb.) and southern pine specimens at a retention of 6.4 kg·m^-3
, and under 11 post-treatment schedules ranging from 50~70 ℃ and 5 different relative humidity conditions. These samples were monitored by expressing residual liquid and analyzing it for hexavatent chromium content. Samples were subjected to AWPA E11-97 (AWPA 1997)standard leaching tests after fixation. Generally, red pine fixed slightly faster than southern pine for most fixation conditions. High temperature, high humidity, fixation conditions during the fixation drying schedules resulted in faster fixation and lower leaching of chromium and arsenic elements compared to low humidity conditions. Copper leaching showed no significant difference under 11 fixation drying conditions for both species. All of the CCA components were leached significantly more in red pine than southern pine. Further work is needed to examine the effects of different fixation drying conditions on leaching from full-size samples and to optimize dry wet bulb depression for fixation drying of CCA treated lumber.