Design of timber-concrete composite floors for fire

Abstract

The popularity of mass timber is occurring at the same time as code developments in the field of structural fire engineering. Due to this synchronism, benchmarked analytical models are needed to design timber- concrete composite floors throughout a fire exposure. Existing analytical models were developed for cross- laminated timber or glue-laminated timber-concrete composite floors with dowel-type fasteners. These models have not been benchmarked against nail-laminated timber (NLT) or screw-laminated timber (SLT)- concrete composite floors with truss plate shear connectors. Data on the experimental behaviour of truss plate shear connectors under direct shear load are presented and compared with typical dowel-type shear connectors. Data on truss plate shear connectors along with experimental data from literature on fire tests of NLT- and SLT-concrete composite floors was used to benchmark analytical modelling techniques for calculating the strength and effective stiffness of the timber-concrete composite floors throughout a fire exposure. The results presented herein can be used to design NLT- and SLT-concrete composite floors for improved fire performance.