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First circular concrete pour in Brussels

Published on 24/06/2021
WTC Brussel

COPRO-certified A+ aggregates from the old WTC towers used in the first circular concrete pour in Brussels

A+- aggregates or high-quality concrete aggregates are concrete aggregates obtained from crushing the high pressure resistant concrete rubble from concrete pavements, linear elements and other equivalent structural elements from buildings and civil engineering works.

Strict acceptance at the crushing plant, knowledge of the origin of the rubble, and stricter requirements for the end product can ensure that these recycled aggregates – provided they meet the requirements of the NBN EN 12620 and NBN B15-001 standards – are extremely suitable for use in higher quality applications such as (poured) concrete and road concrete.

The COPRO certification for high-quality concrete aggregates A+ underpins confidence in the quality of these recycled aggregates, so that they can be used just like natural aggregates in high-quality concrete applications such as in-situ concrete and road concrete.

There are currently 16 production units in Flanders spread over 8 different producers that have a COPRO technical datasheet for high-quality concrete aggregate (A+). The first application is currently underway for high-quality mixed aggregate (B+).


Cradle to cradle

One of these producers is the company All Belgian Recycling (ABR). Thanks to the continuous commitment and know-how of this group as well as the scientific projects it supports, it succeeds in bringing recycled aggregates to such a level that they can be used in higher-value applications. This in turn leads to reduced use of natural resources and to a more sustainable society.

In 2019, this expert in ground and demolition works started demolition of the old WTC towers in Brussels. During the dismantling phase, De Meuter collected and sorted the demolished rubble from the base and the towers. Approximately 30,000 tonnes of rubble was transported to its All Belgian Recycling (ABR) recycling and crushing site in Grimbergen.

Here the rubble was processed at its optimised fixed crushing plant and the obtained high-quality aggregates were correctly stored. The required analyses were performed and the obtained A-aggregates were certified by COPRO.

These high-quality, high-value aggregates from the WTC towers were in turn integrated into new concrete by CCB, resulting in 30,000 tonnes of new “cradle-to-cradle” certified concrete intended for the ZIN project. This makes CCB the first company in the Benelux, and the second worldwide, to receive the international C2C silver certificate for its ready-mixed concrete.

All of this resulted in the first circular concrete pour in Brussels – and by extension, the Benelux – on Friday 11 June. The site of the event was the ZIN project, Befimmo’s innovative and multifunctional project in the Brussels North district, where the high-quality recycled rubble from the old WTC towers was reused.

This is the first time that this process has been used in Belgium on such a scale for these applications (compression slabs, floor slabs and prefab slabs). Due to the ever-increasing demand for circularity, this innovative way of working will increasingly be introduced. It not only reduces the waste mountain, but also the environmental impact. COPRO is happy to help further develop circular concrete in Belgium!