French Construction Group Tests Roads Made From Scallop Shells

French construction group Eiffage is testing a low-carbon concrete that replaces a portion of cement with recycled scallop shells in Calvados [1, 2].

The project aims to lower the carbon footprint of road infrastructure while addressing the environmental burden of organic waste from the maritime sector.

Construction on the pilot project began in early 2025 ^[1]. The work is located on a departmental road near Courseulles-sur-Mer in the Calvados department of Normandy [1, 2]. By substituting part of the traditional cement with processed shells, Eiffage intends to reduce the total CO2 emissions associated with road building [1, 2].

This innovation targets a significant waste stream in the region. Approximately 20,000 tonnes of scallop shells are discarded each year in Normandy ^[3]. These shells, typically viewed as a byproduct of the fishing industry, contain minerals that can be repurposed for construction materials.

Eiffage developed the initiative in partnership with local authorities in Calvados [1, 2]. The collaboration allows the company to monitor the durability and performance of the shell-integrated concrete under real-world traffic conditions. The project serves as a test case for whether this circular economy model can be scaled to other regions with high shellfish production.

The use of recycled shells helps divert waste from landfills and reduces the reliance on energy-intensive cement production. Cement manufacturing is a primary driver of global industrial carbon emissions, making the search for viable substitutes a priority for European infrastructure goals [1, 2].