Charring rates for cross-laminated timber panels exposed to standard and parametric fires

The present study tested the charring rates for cross-laminated timber panels (CLT) exposed to standard and parametric fires. A series of fire tests were performed on horizontal cross-laminated timber panels exposed to EN 1991-1-2 Standard and Parametric temperature-time curves, and a “Swedish” curve. A large gas-fired horizontal furnace was used in the experiments. The char depth was measured through all stages of the fires. The objectives were; to examine the charring rate of CLT panels and whether the charring changed through the fire stages, to investigate if the charring rates for the various temperature-time curves were different, and if the rates were affected by the panel thicknesses. Timber panels of three different thicknesses were tested to investigate a thickness effect. The results illustrate that the charring rate for CLT panels exposed to various fires can vary greatly. Fast temperature growth gave faster charring rates. The thickness of the panels did not have an unambiguous effect on the charring rate. The charring rate of wood exposed to fires of long durations became constant after a while.