Summary
Carefully extracting reinforced concrete (RC) elements and steel beam profiles from soon-to-be demolished structures and reusing them in new load-bearing systems is an emerging circular, extremely low-carbon strategy for new construction. Producing building floor systems typically accounts for the most significant part of the upfront carbon footprint of buildings. Preliminary work suggests that combining reused steel and RC elements to build floor systems reduces global warming potential by up to 95 % relative to their conventional flat RC slab counterparts. However, interdisciplinary research is still needed to optimise such systems, develop appropriate details and bolster a broad implementation by the industry.
Within such a context, the first objective of this proposal is to define a competitive design brief for this new circular floor system, incorporating architectural, structural engineering and constructive constraints. Then, the project aims to develop new demountable shear connectors between saw-cut RC slabs and standardised steel beam profiles – both being reclaimed from deconstruction sites – to construct a new floor system insensitive to material-property uncertainties and geometric tolerances expected in reclaimed elements. This will be realised by leveraging a new concept that defies the current paradigm where controlled slip at the beam-slab interface will be allowed. The validation of this new connector and the development of guidelines for the structural design will be possible through simulation-based engineering design and physical experimentation. Finally, the design will be complemented through a parametric life cycle assessment (LCA) comparing the environmental impacts of the all-reuse floor system to the ones of conventional solutions. Design guidelines for industry stakeholders will summarise the findings, including considerations on the best deconstruction methods to maximise the reuse potential of the reclaimed elements.
This research project seeks a close collaboration with the steel constructor Morand SA, to ensure greater industrial relevance and economic viability. Feedback will also be sought from other stakeholders throughout the project. Combining the highly complementary expertise of SXL (IA) and RESSLab (IIC), the project is at the crossroads of architectural design, sustainable and circular construction, computer-aided design and building experience modelling (BEM), life-cycle assessment (LCA), and experimental methods across scales, which falls directly within the strategic topics of this call (construction materials and technologies, carbon footprint and building LCA, digitalisation in the AEC sector).
General information
Project Lead: Dimitrios Lignos, Corentin Fivet
Project Team: Lise Bachmann, Célia Küpfer
Fribourg Partners: Morand SA