80 metric tons of recycled concrete in a brand new building

Posted on 18 February 2020.

In Chartres, "Le Onze" is a pioneering innovative construction, thanks in particular to recycled concrete.

At first sight it looks like any other building. But only at first sight because in reality, the apartment building known as "Le Onze" with its 12 housing units on three floors, undoubtedly represents the future.

In Chartres, this demonstrator project led by the developer Pierres & Territoires Eure-et-Loir PROCIVIS is innovative in a number of ways. Starting with the large-scale use of recycled concrete which places the building in a fantastic circular economy approach.
The recycled concrete aggregate used in "Le Onze" comes from the demolition of old buildings in the town. From a technical point of view, the concrete from demolition works is recycled by the construction and demolition waste specialist Granudem.

The concrete is then fed back into the manufacturing process to make concrete structures using ready-mixed concrete and prefabricated industrial products - for example slabs, double walls and stairs.
In total, getting on for 80 metric tons of recycled aggregate was incorporated into the 400 m3 of concrete used on the project.
This XXL challenge was realized as a result of the close collaboration between the operational stakeholders and the industrial sectors involved in the works, including the concrete industry federation (FIB) and the Cerib (concrete industry study and research center), which helps manufacturers to develop new products.
To ensure the success of the environmentally-friendly project, the developer Pierres & Territoires Eure-et-Loir Procivis laid down two prerequisites: no change in working methods for local businesses, and control of construction costs and therefore the price of the housing units - capped at €3100 per square meter.  

A holistic approach

The experimental building was built in compliance with the E+ C- (E+ for positive energy and C- for carbon reduction) standards, which measure the environmental impact of a structure over the whole of its life cycle from construction to demolition.According to the contracting authority, the real estate project has probably saved some 360 metric tons of carbon – an impact that is 20% less than on traditional constructions.
After twelve months of work, "Le Onze" is scheduled for delivery in February 2020.