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PRECAST CONCRETE ELEMENTS138 CPI %u2013 Concrete Plant International %u2013 2 | 2026 www.cpi-worldwide.comReusing large concrete rubble into prefabricated structural walls is a novel construction process offering a way to reduce the environmental footprint of concrete up to 80%. Instead of crushing demolition concrete rubble into recycled concrete aggregate, this PhD research aims to directly reuse the large rubble pieces from demolition as masonry elements of prefabricated load-bearing walls. It implies sourcing the %u201cwaste%u201d from recycling centres, scanning them in 2D using smartphone photos, and then assembling them on the tilting table of prefabrication facilities. This approach is implemented at full scale for a two-story demonstrator and a public pavilion, both designed and built by the author, which also feature reused concrete slabs sawn from a building prior to its demolition.Reuse rather than recycleConcrete is, volume-wise, the most wasted material worldwide after excavated soils [1], making the construction industry the largest waste generator [2]. Concrete is also the most used material worldwide, second to water [3]. Its numerous qualities, such as availability, low cost, versatility, workability, strength, and durability, make it a suitable choice for building structures. However, producing and pouring new concrete is the largest contributor to the construction industry%u2019s detrimental environmental impact [4]. The production of cement is responsible for 8%u20139% of global anthropogenic CO2 emissions [5]. Linking the need for CO2-intensive concrete with the availability of disused concrete rubble, several circular strategies propose using a portion of concrete waste in new concrete structures. While the use of crushed concrete as a replacement for natural aggregates in new mixes, i.e., concrete recycling, is gradually adopted in the construction industry, it does not significantly reduce the embedded CO2 of these mixes because similar amounts of cement are used as in regular mixes [6]. Concrete recycling and optimised concrete recipes won%u2019t suffice to meet the soon-to-be-imposed quota for new construction. Given the high resource demands and CO2 emissions associated with concrete production, the reuse of concrete in structural elements %u2013 the most material-intensive part of buildings %u2013 offers significant benefits [7]. Reuse, distinguished from recycling, avoids the energy-intensive retransformation of materials to recreate a product of similar properties. Reusing concrete elements is a little-implemented strategy, yet it can save up to 94% of the upfront carbon emission of concrete construction [8]. A distinction is made here between reusing elements that originate from the careful dismantling of structures, e.g., using diamond saws, and reusing rubble from conventional demolition, e.g., produced by demolition excavators. Reusing concrete rubble remains little explored in the construction industry and academia, despite its widespread availability. Reuse of rubble is considered here as an upcycling strategy, in contrast with concrete recycling, which is considered downcycling due to the reduction of size and degradation of the bond between aggregates. In this research and article, large concrete rubble is embedded within prefabricated structural walls, a revolutionary method for saving large quantities of concrete.Trust through full-scale demonstrators%u201cIf industry had a better way to do things, it would exist already.%u201d%u201cWe can%u2019t insure this, it has never been done, it%u2019s too risky.%u201dReusing concrete rubble into prefabricated load-bearing components is not just an idea anymore. It%u2019s a tangible and replicable method which have been proven through multiple full-scale demonstrators in Switzerland. To reach this point, the author collaborated with colleagues at EPFL, civil engineering firm Nicolas Fehlmann Ing%u00e9nieurs Conseil, prefabrication company Prelco, transport compagny Friderici Special and the recycling centre SRREC to develop new prefabrication processes and assembly methods to bring prefabricated walls from concrete rubble to life (Fig. 1). Using those walls and reused concrete slabs sawn from a building prior to its demolition, Maxence Grangeot and his team first built a 2-storey building mock-up (Fig. 2) in Fribourg, Switzerland, and then reassembled those same elements into a pavilion Reusing large concrete rubble for load-bearing structures with minimal environmental impactInnovative approachn Maxence Grangeot, EPFL, Lausanne, Switzerland