CLT-Steel Composite Floors for Sustainable Multi-Storey Construction

This thesis encompasses the investigation of a novel proposed construction system that pairs Cross-Laminated
Timber (CLT) floor panels with steel-frame multi-storey construction.
As a substitute for concrete floors, the promise of CLT lies in its reduced embodied carbon, and its
lightness, which gives the promise of reduced material usage and a reduction in the environmental
impact of a multi-storey building overall.
In addition to clarifying the environmental benefit such a system provides, this thesis seeks to determine
whether forming composite sections from the CLT panels and the steel beam, can lead to meaningful
enhancements to the section stiffness in bending. Finite element analysis is applied for this task,
necessitating first a methodology for modelling CLT to capture its relevant complexities as a material,
and subsequently incorporation of the behaviour of the joints between structural elements in the
proposed system, with the key characteristics of the materials and joint models validated against physical
test data.
Focusing predominantly on a slimfloor arrangement of panels and beams, the study provides the first
evaluation of the effective width of CLT floor panels when acting compositely with steel beams, provides
a prediction for composite action CLT panels and Asymmetric Steel Beams (ASBs) with a series of
connectors, and identifies areas of development within the system that could bring about increased
composite benefits.
The outcomes of the study are that in a slimfloor arrangement with contemporary panels, beams and
connectors, the composite enhancement is small but measurable, and that with changes and
development to the system components, much larger composite enhancement effects could be
generated.