PhD position at University of Pau & Pays Adour (BECCoH project)
description de l'offre: BECCoH research project presentation BECCoH intends to answer to new Energy and Environment challenges by increasing performance and reducing environmental cost of concrete and cement-grout materials based on seashell incorporation.
France is the first oyster producer country in Europe and oyster seashells are prominent in the Aquitaine region, especially in the Arcachon bay area whose economic activities are based on to pillars: oyster farming and tourism. This important oyster production generates an important amount of seashell under-product wastes, which are usually dumped in local harbors or directly stored on the littoral, with high negative impacts on both natural eco-systems and tourism. In the same time, there is currently a decrease in the production capacity of local quarries for construction aggregate supply and the exploitation of distant quarries increases the global environmental cost of the concrete used locally. Therefore a first objective of the BECCoH project is to propose a new formulation of environmental-friendly concretes where an important part of the granular skeleton is replaced by oyster seashells produced locally while ensuring similar durability and mechanical performances compared to classical and normalized concrete formulations. A unique pilot construction site will be installed and instrumented during the project in collaboration with the Arcachon bay area authorities to test the performance of these new bio-hybrid concrete under real life conditions.
In addition, nacre – the iridescent material in seashells – is one of many natural materials employing hierarchical structures to achieve high mechanical performance from relatively weak constituents. Nacre has bio-inspired and motivated many researchers in the last ten years to understand, mimic and transfer to synthetic materials its unique mechanical performance. The second objective of the BECCoH project is hence to improve performance of cement-grout material used for geothermal well cementation by incorporating nacre-based under-product in their formulation. Well cementation is used to mechanically link tubing to the geological formation and it has a crucial role to avoid mass transfer between the different geological layers during production. In geothermal context, an ideal cement-grout should present in the same time very antithetical performances (e.g. low density, high strength, high ductility), which cannot be achieved by classical synthetic materials but are usually achieved by natural ones because of their unique hierarchical design. Incorporating nacre-based seashell under-products in cement-grout formulation may help in reaching such an ideal material. A direct partnership with BOPS Company, specialist of well cementation and production, will allow direct and fine comparison with classical cement-grout formulation actually used on-field and will allow the study of the new formulations proposed in the context of real industrial conditions.
date de debut: 2018-12-03
For more details on the project, job details and application procedure, we refer to the attached pdf document