Within IRDL, Mathieu Audren has developed compressed earth blocks for sustainable construction.

Mathieu Audren, chercheur·e au sein de IRDL (Institut National Polytechnique de Bretagne).

Thèse soutenue en 2024 à l'école doctorale École doctorale Sciences Pour l'Ingénieur (Lorient ; 2022-....).

Référencée dans le réseau ABES/STAR, cette thèse répond aux critères de rigueur de l'enseignement supérieur français.

The thesis of Mathieu Audren addresses a fundamental issue for the construction sector: how to meet the growing demand for housing while minimizing environmental impact? This question is particularly urgent, especially in a context where urban populations continue to rise. The answer lies in the industrialization of compressed earth block production from co-products of quarries. This innovative approach not only diversifies the materials used but also reduces dependence on non-renewable aggregates, the use of which has exploded over the last century. Indeed, aggregates, often extracted from quarries, are limited resources that, once depleted, cannot be renewed.

The research focuses on optimizing the formulation of the blocks and adapting the vibro-compaction process. By characterizing the co-products and conducting geotechnical tests, Audren demonstrates that recycled materials can achieve satisfactory mechanical properties. For example, case studies in West Africa have shown that the use of raw earth, combined with co-products such as quarry residues, can produce blocks with strength comparable to that of traditional materials. This paves the way for more environmentally friendly construction while addressing the growing housing needs.

The environmental impact of construction is a hot topic. In France, new construction activity increased by 3.2% in 2022, while the use of aggregates grew by 340% between 1900 and 2005. These figures highlight the urgency of adopting sustainable solutions. Compressed earth blocks, as a viable solution, could reduce carbon emissions from the sector. By integrating recycled materials, this construction method could also contribute to resource circularity. In a context where climate change is a pressing reality, this approach could play a key role in reducing the carbon footprint of buildings.

However, the transition to sustainable building materials requires significant investments. Decision-makers must understand that increasing financial flows towards low-carbon construction solutions is not only beneficial for the environment but also for the economy. By promoting the industrialization of compressed earth block production, we can create jobs while addressing the housing crisis. For example, initiatives in West Africa have shown that training local workers for the production of these blocks can stimulate the local economy while meeting fundamental housing needs.

It is time to rethink our approach to construction. The results of this thesis show that alternatives exist and are ready to be implemented. The question is: will we be able to seize this opportunity to transform our urban landscape and reduce our ecological footprint? By integrating vibro-compacted raw earth blocks into our construction practices, we have the opportunity to build a more sustainable future.

In conclusion, Mathieu Audren's research is not limited to a simple technical study. It raises crucial questions about how we can reconcile urban development and the preservation of our environment. By promoting sustainable building materials, we can not only meet the growing demand for housing but also contribute to a future that is more respectful of our planet. The challenges are numerous, but solutions exist. It is time to act.

Sources et accès

Mathieu Audren. Formulation, mise en oeuvre et performances de blocs de terre crue vibrocompactés. Génie civil. Université de Bretagne Sud, 2024. Français. ⟨NNT : 2024LORIS693⟩. ⟨tel-04940214⟩

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