Articles

UHPC Giant Tiles for Long-Lasting Watertightening of a Subsurface Waste Storage: From Conceptual Design to Prototyping and Trial Site Ageing for Qualification

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Abstract

Protecting and ensuring watertightness of a subsurface nuclear waste storage facility for over 300 years, so that underground water around the site can be preserved from radioactive pollution, represents a challenge for which traditional technical solutions may need to be improved / complemented. ANDRA, the French operator of the facility, has identified UHPC as a potential solution to cover the site and complement the natural soil, bituminous membrane and gravel layers which already protect the waste barrels. From the attractive conceptual design of a UHPC tight layer, it turned out necessary to check technical and economical feasibility through a detailed design stage, considering service loads but also accidental seismic or storm cases, and constructibility issues. This engineering task was carried out by LRIng design office, with the advisory help of various experts in UHPC, seismic and geotechnical engineering. Strength and stiffness optimization as well as durable anchoring of the « tiles » to resist high winds and keep efficiently assembled were demonstrated with realization, by Innobéton precasting firm, of prototype elements installed onsite to demonstrate performance. The paper will emphasize how this detailed engineering project enabled progress in demonstrating the ability to constitute a complete durable continuously watertight jigsaw puzzle of UHPC elements properly anchored in the ground, meeting the durability expectation of the operator and thus possibly implemented in the future. Moreover, this project might derive into further technical alternatives and solutions for similar or further demands of long-lasting « roofing ».

Keywords: tiles, protection, watertightness, durability, constructibility, prototype

How to Cite:

Lamoureux, G., Ricciotti, R., Mazzacane, P., Laugé, J., Nazé, P., Toutlemonde, F. & Marchiol, A., (2023) “UHPC Giant Tiles for Long-Lasting Watertightening of a Subsurface Waste Storage: From Conceptual Design to Prototyping and Trial Site Ageing for Qualification”, International Interactive Symposium on Ultra-High Performance Concrete 3(1): 91. doi: https://doi.org/10.21838/uhpc.16700

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