INVESTIGATION OF CLT PANEL DEGRADATION DURING HEATING AND COOLING PHASES OF FIRE

The research presented in this paper investigates the behavior of Cross-laminated timber (CLT) under fire exposure during the heating and cooling phases. A sample CLT panel was exposed to a 60 min heating phase as per the ISO 834 standard time-temperature curve, following which it was removed from the furnace and left to cool at ambient temperature. Due to char formation and availability of oxygen during the intended cooling phase, the intensity glowing combustion was growing and resulted in increasing temperatures and even flaming combustion in its latter stages. The char layer thickness doubled during the intended cooling phase under the experimental conditions. Temperature profiles measured parallel and perpendicular to isotherms indicated significant underestimations associated with the perpendicular orientation. The study highlights the need for consideration and further investigation of the cooling phase and its impact on structural design and fire investigation.