Determination of the water sorption properties and preliminary results from field tests above ground of thermally modified material from industrial scale processes
C R Welzbacher; A O Rapp
In this study the differences in moisture behavior and durability above ground of heat treated wood originating from different European industrial heat treatment plants by means of the water sorption properties as well as field tests were examined. The manufacturers of heat treated material were: PLATO Hout B.V./Netherlands, Thermo Wood (Premium wood)/ Finland and Menz Holz/ Germany,
where Oil-Heat treated Wood (OHT) is produced.
Temporary evaluation of field tests showed a substantially improved resistance against biological attack of the thermally modified material compared to controls. The results of the laboratory tests regarding the determination of the Moisture induced Risk Index (MRI) showed a significantly reduced MRI of heat treated material compared to references. Material from the PLATO process and Oil-Heat treated material revealed significantly lower MRI values than Thermowood. Natural weathering above ground had so far no significant influence on the MRI of thermally modified specimens compared to the initial values.
Keywords: Thermal treatments, thermal modification, field testing, moisture content, Moisture induced Risk Index (MRI)