Low carbon hybrid timber-steel structures in fire

The built environment is one of the largest producers of carbon emissions, responsible for around 38% of global emissions. Hybrid timber-steel structures utilise a traditional steel frame but use Cross Laminated Timber (CLT) for floor slabs which have the potential to reduce embodied carbon in the built environment. However, the introduction of a combustible structure leads to unknown fire behaviour in the event of a fire, and this represents the largest barrier to the use of timber in buildings. Hybrid timber-steel systems are also sufficiently new that the structural behaviour in ambient conditions is not well characterised.

This project aims to better quantify the fire performance of these low carbon hybrid timber-steel systems. It will focus on the thermal characteristics to quantify heat transfer through the element, and incorporate char oxidation of the timber. The burning of timber is complex and this is not captured by simple heat transfer models that do not consider the degradation of the material and the potential crushing under mechanical load.

This model should provide the relevant thermal input to (i) run mechanical models to demonstrate the structural stability of the hybrid timber-steel system and (ii) demonstrate self-extinction of the timber, or otherwise demonstrate that the building will be fire-safe even if the timber burns. This will enable engineers to design fire-safe low carbon structures that can reduce carbon emissions in the built environment.

There is potential for industry collaboration with companies specialising in hybrid construction and with timber manufacturers.

The candidate should have a Bachelor's or Master's degree in a relevant engineering discipline (e.g. mechanical engineering, civil engineering, fire safety engineering) or similar STEM background (e.g. applied physics, mathematics or data science).

The proposed start date is 2nd September 2024 but other start dates are possible and applications can be accepted all year round. Informal enquiries, please contact Dr Martyn McLaggan <m.s.mclaggan@sheffield.ac.uk>.