Issue 4

This paper describes how a constrained layer damping system may be incorporated into a composite floor, potentially improving the floor's dynamic performance by a factor of 2 or more.

Timber frame buildings may have low embodied energy, but have the disadvantage of low thermal mass. Steel and concrete composite construction provides good thermal mass but is becoming less economic with the increasing cost of steel. This paper presents results from testing of a composite system that allows the use of timber with improved structural efficiency and increased thermal mass. The composite system consists of a concrete slab cast on profiled steel decking acting compositely with glue-laminated timber beams. Composite action is achieved with coach screw shear connectors between the beams and slab. The connectors have been tested in ‘push-out’ shear tests and a three-point bend test of a full-scale floor slab has been completed. The composite system is more than three times as stiff and almost twice as strong as the same beam/slab configuration without composite action. Existing analytical and design methods are compared to finite element predictions and the experimental results and show good correlation. Richard Persaud Dr Digby Symons, University of Cambridge, Department of Engineering, Trumpington Street, Cambridge, CB2 1PZ