Reuse potential and circularity index, applied to the construction sector

Context and challenges

This research is part of the construction sector’s transition towards a circular model, aimed at extending the lifespan of end-of-use elements when they can still fulfil their original function. One of the major challenges is to dissociate the actual lifespan of components from their functional lifespan, which is linked to their robustness and their capacity to be reused. In this context, the reuse of materials, and in particular structural reuse, appears to be a key strategy for reducing the environmental impact of buildings and promoting more sustainable resource management.

Objectives and method

The thesis proposes to address two questions specific to the practice of structural reuse: the residual properties of reinforced-concrete elements during deconstruction, and the assessment of the reuse potential of elements.

In practice, the study of the residual properties of reinforced-concrete elements will draw on the inspection methods commonly used for the rehabilitation of reinforced-concrete structures. It relies on case studies of real structures. A first study in this area would be to compare the variability of mechanical properties (compressive strength) and durability properties (carbonation front) for precast concrete elements and cast-in-place concrete elements.

The other topic of study, the assessment of reuse potential, builds on A. Lachat’s work and proposes to calibrate the various criteria of the indicator using real data from deconstructed structures. Ultimately, the indicator is intended to be a decision-support tool complementary to an LCA at the deconstruction-study stage (PEMD or reuse audit). It will confirm, or not, the technical and operational feasibility of reuse in a given context.