《994_ftp》.pdf

FIRE AND MATERIALS Fire Mater. 2010; 34:1–19 Published online 25 March 2009 in Wiley InterScience (). DOI: 10.1002/fam.994 Experimental fire analysis of steel-to-timber connections using dowels and nails Andrea Frangi∗, †, Carsten Erchinger and Mario Fontana Institute of Structural Engineering IBK , ETH Zurich, 8093 Zurich, Switzerland SUMMARY The paper describes and discusses the results of an extensive testing programme on the structural behaviour of timber connections under ISO-fire. The results of reference tests performed at normal temperature are also presented. From the variety of timber connections multiple shear steel-to-timber connections with dowels and slotted-in steel plates and connections with steel side plates and annular ringed shank nails were experimentally studied. Particular attention was given to the analysis of the efficiency of different strategies in order to increase the fire resistance of the timber connections. The test results showed that unprotected multiple shear steel-to-timber connections with dowels designed for normal temperature reached a fire resistance of about 30 min. A reduction of the load level applied during the fire did not lead to a significant increase of the fire resistance. By increasing the side timber members as well as the end distance of the dowels by 40 mm the connections reached a fire resistance of more than 70 min. Connections protected by timber boards or gypsum plasterboards showed a fire resistance of around 60 min. Thus, from a fire design point of view these strategies were favourable in order to increase the fire resistance of the connections significantly. Unprotected connections with steel side plates and annular