Demountable composite beams for a circular economy: Large‐scale beam tests

The circular economy approach has been introduced to the construction sector to design out waste, reduce carbon emissions and energy use in production of primary materials and achieve resource efficiency. ‘Design for deconstruction’ is increasingly important for a sustainable economy, especially for composite structure that is deemed as resource‐efficient in the first cycle of use. With this background, research has been conducted to facilitate the use of demountable composite beams in steel‐framed structures. This article presents the results of two 6 m full‐scale composite beam tests with prefabricated composite slabs. Demountable shear connectors were used, which have been newly developed within the frame of an EU project. The nominal degree of shear connection of the composite beam specimens was 0.37, which was slightly below the required 0.4 specified in EN1994‐1‐1 for welded shear studs. Based on the experimental observations, it can be demonstrated that (1) the tested demountable composite beam produced higher resistance but lower stiffness values than a comparable reference composite beam with welded shear studs; (2) the beam specimens showed a good plastic behaviour with high ductility despite the non‐ductile nature of the applied demountable shear connectors. Remarks on the demountability of the developed demountable composite beams are provided.