A recycling system installed at Heidelberg Materials’ Greenwich concrete plant is recovering aggregates and cementitious fines* from returned concrete for use in new materials, as well as recycling water used to wash concrete trucks.
Heidelberg Materials UK says the installation has enabled the London site, at Victoria Deep Water on the River Thames, to achieve its target of producing zero concrete waste. Recovered aggregates and cementitious fines are returned to material production, while all water used for cleaning trucks can be reused.
The company said the system forms part of efforts to develop the Greenwich site as a circular construction materials hub.
The plant can also supply recycled crushed concrete aggregate (CCA), which can replace primary aggregate in ready-mixed concrete. Its lower-carbon concrete offering includes supplementary cementitious materials such as ground granulated blast-furnace slag (GGBS), limestone fines, natural pozzolans and calcined clay.
CarbonCure technology installed at the plant provides a further route to reducing the embodied carbon associated with concrete. The proprietary process injects manufactured CO₂ into fresh concrete, where it reacts to become permanently mineralised.
Heidelberg Materials says the technology can reduce the CO₂ associated with concrete by around 7–11kg/m³. The resulting mineralisation is also said to increase concrete strength sufficiently to allow cement content to be reduced by an average of 5%.
“Our Greenwich concrete plant is a great example of our commitment to investing in innovation and decarbonising our business so that we can provide our customers with lower carbon construction materials that support the circular economy,” said Daniel Clayton, Concrete Technical Director at Heidelberg Materials UK.
The Greenwich site also houses a concrete laboratory and Heidelberg Materials’ evoHub training centre, where contractors, consultants and engineers can see lower-carbon concrete technologies in practice.
* Cementitious fines: fine, cement-rich particles recovered when waste or returned concrete is processed.
