The elastic and ductile behaviour of CLT wall-floor connections and the influence of fastener length

An investigation was carried out to examine the influence of the fastener length on the elastic and ductile failure behaviour of typical steel-to-timber bracket connections in Cross Laminated Timber (CLT) manufactured from C16 spruce. The behaviour of single screw-type fasteners within CLT of length 25 mm, 50 mm and 75 mm are examined under tension and shear loading. Multiple screw-type fasteners have been utilised to examine monotonic and cyclic behaviour of steel bracket-fastened CLT connections under shear and tension loading. Characteristic values of the experimental results are compared to analytical models from current timber design codes and the literature. The length of fastener has been shown to influence the failure strength and ductility of the connection. The overstrength factors and strength degradation factors have been shown to be similar, regardless of fastener length, and conservative values are recommended.This work has been carried out as part of the project entitled ‘Commercialisation of Irish Cross Laminated Timber” (project ref. 15/C/694) funded by the Department of Agriculture, Food and the Marine of the Republic of Ireland. The contribution of the technical staff of the College of Engineering and Informatics, NUIG, in particular, Peter Fahy, Colm Walsh and Gerard Hynes, is acknowledged.peer-reviewed2021-03-3