Innovative composite floors for sustainable schools

Read our engineer’s thoughts on why composite floors offer an intriguing solution to the demand for new schools and sustainable structures in the UK:

With a high demand for new schools and sustainable structures in the UK, composite timber and concrete slabs offer an intriguing solution to meeting the demand whilst minimising whole-life carbon. This is further to providing fire, acoustic, and thermal mass benefits.

As part of the GenZero initiative, investigations have taken place into a prototype panel consisting of a precast concrete deck on glulam ribs with two interlayers. A 24mm thick timber deck provides permanent formwork, and a 5mm acoustic damping layer reduces sound between floors.

Achieving a high level of precision

The concrete deck eliminates the need for carbon-intensive floor finishes. By manufacturing offsite in a controlled environment, a high level of precision can be achieved ensuring the slabs fit precisely on-site. The design of the deck comfortably achieves strength and deflection criteria, but adequate shear connectors are required to satisfy dynamic requirements.

Furthermore, the presence of an interlayer even 1mm thick has a greater impact on the reduction in the stiffness of the connector than the thickness of the interlayer. However, the most important factor in the design of the shear connectors is the need for them to be constrained vertically (for example, by using glued dowels or screws). One of the most promising aspects of this research is that the current design can be delivered successfully using UK-grown timber.

This thought-piece was written by Austin Young, a Structural Design Engineer for Mosaic CSE.