Towards alternative fire design solutions for wood-to-wood connections

A lack of available reference data exists for modelling wood structures in fire. This is of importance where protection schemes are evaluated as part of an alternative solution process for new and old structures. Herein, a mortise and tenon connector (Eastern Hemlock of heritage value) was subjected to a localised pool fire exposure of approximately thirty minutes. Interior connection temperature was measured. Narrow Spectrum Illumination technologies were utilised to characterize the char layer formation and the generation of embers which may contribute to fire spread. Results indicated that in this experiment the observed char rate was faster than codes prescribe and was non-linear. A dynamic char rate model may be needed for accurate fire performance calculations of wood members. The corner-rounding effect is more severe at interior interfaces suggesting that the heat flux generated from the burning wood could be a large contributor to char rate. Although the mechanical integrity of a traditional all-wood mortise-and-tenon connection appears largely maintained post-fire, current codes may not accurately predict post-fire outcomes.