Fire Safety Science Digital Archive

In heavy timber structures, double-shear connections, including wood-wood-wood (WWW), wood-steel-wood (WSW) and steel-wood-steel (SWS) connections with either bolts or dowels as fasteners, are widely used to assembly structural members and transfer loads. However, connections with metal fasteners and components are potentially venerable links in fire exposure. A number of efforts have been devoted to study the fire performance of timber connections in the last two decades. With the knowledge and experimental data generated, new attempts have been made in order to develop new calculation methods and improve design rules for timber connections in fire. In this paper, existing modells are discussed and new correlations are presented for the calculation of the fire resistances of double-shear timber connections. Various factors, i.e. timber thickness, fastener diameter, and load ratio are considered in the correlations. Comparison between the predictions using the correlations and the measured results in fire-resistance tests shows good agreement. For timber connections with protective membranes, the component additive method (CAM) can be used by adding the additive fire resistances of the protective membranes to the fire resistances of unprotected timber connections. Connections with concealed fasteners and intumescent paint are also discussed in this paper.