Recycled aggregates: CAPREMIB supplies concrete blocks for the National Circus Arts Centre

Reusing railway materials within a circular economy framework

Following the renewal of 20 kilometers of railway tracks between Châlons-en-Champagne and Reims by SNCF Réseau, bi-block concrete sleepers have been repurposed in a new production cycle.

In total, 30,000 railway sleepers were recycled. After crushing, approximately 5,000 tons of concrete were transformed into aggregates of two distinct sizes. These materials were then incorporated into the manufacture of 40 concrete blocks destined for the National Circus Arts Centre.

The operation also enabled the removal of 700 tonnes of steel from the processing of the sleepers.

This approach is in line with the principles of...circular economywhich aims to extend the lifespan of materials and limit the use of virgin natural resources.

Concrete blocks intended for technical uses in live entertainment

The blocks manufactured by CAPREMIB will have several functions.

Initially, they will serve as display supports as part of the 40th anniversary celebrations of the National Circus Arts Centre. They will then be used as ballast elements for big tops, gantries or masts.

This type of structure requires controlled mechanical characteristics to guarantee the stability of the installations. The quality of the concrete is therefore a crucial criterion for meeting the site's operational requirements.

As an example, similar ballast blocks are regularly used on construction sites, during temporary events, or to secure outdoor equipment.

A concrete formulation that complies with regulatory requirements

The integration of recycled aggregates into concrete production is now subject to a precise regulatory framework.

According to CAPREMIB, the formulations used meet the requirements of the standard NF EN 206+A2/CN I of December 2025, which notably regulates the manufacture of concrete incorporating recycled aggregates.

“CAPREMIB is gaining increasing experience in using recycled aggregates in its concrete mixes. Their performance is certified by the NF EN 206+A2/CN I standard of December 2025 relating to the manufacture of concrete including recycled aggregates.”

"We are able to achieve the same characteristics as traditionally prefabricated concrete, as evidenced by the trials and tests carried out."

According to the company, the controls carried out allow for performance comparable to that of conventional prefabricated concrete.

This approach, however, requires rigorous work in characterizing recycled materials, formulation, and quality control. Design offices, laboratories, and production teams play a crucial role in validating the performance achieved.

A shared approach among the project stakeholders

The National Circus Arts Centre wanted to integrate an environmental dimension into this operation.

"At the National Circus Arts Centre, we are committed to ensuring that our projects are part of a responsible and sustainable approach."

"We are convinced that it is possible to combine technical requirements, quality and respect for natural resources."

This collaboration is based on a shared commitment to prioritizing short supply chains. The manufacturing took place in the Marne region, using materials sourced from a regional construction site, thus minimizing transportation needs and promoting the local use of available resources.

A strategy committed to low-carbon concrete

This operation is part of a broader approach undertaken by CAPREMIB to reduce the environmental footprint of its construction systems.

The company had already used aggregates from the demolition of a Reims Habitat housing block in 2025. After crushing, these materials were incorporated into prefabricated concrete intended for the construction of the stands in the Neoma Business School amphitheater in Reims.

This continuity reflects a strategy implemented since 2018 focused on the development of low carbon and very low carbon concretes, associated with the valorization of recycled materials.

In a context where the construction industry is seeking to reduce its consumption of natural resources and associated emissions, the reuse of aggregates from the deconstruction or renewal of infrastructure is emerging as an increasingly explored avenue. Its implementation, however, remains contingent on the availability of these deposits, their quality, and compliance with the specific technical requirements of each project.

The project carried out for the National Circus Arts Centre illustrates the increasing use of recycled materials in prefabricated concrete. It also demonstrates that local approaches, combined with rigorous quality control, can contribute to developing construction solutions that meet the sector's technical requirements.