A 23% REDUCTION IN CO₂
RECYCLED CONCRETE IS A REALITY
We have just cast the first elements using recycled concrete elements — an exciting development within recycling in the concrete industry. The recycling of concrete is not new. For many years, we have cast elements using crushed concrete, which replaces a proportion of the stone and gravel in the concrete mix. What is new is that we have cast elements using whole pieces of recycled concrete elements, which replace a proportion of the concrete consumption — and thereby reduce cement consumption.
The recycled concrete elements that are cast into the concrete walls originate from demolished buildings in Denmark and are supplied in close collaboration with Tscherning.
— Together, we have found an efficient solution for grabbing the elements down from the building rather than cutting out the element pieces. With this solution, we are not adding any further processing and therefore no additional energy or blades, which would have a negative impact on the CO₂ footprint, says Mikael Jakobsen, Demolition Director at Tscherning.
An added bonus is that the concrete elements containing recycled concrete are unique and give the cast elements a rustic character — a distinctive quality that some of us will think is pretty cool : )
Lars Reimer, Technical Director at CRH Concrete, confirms: — Together with Tscherning, we have looked at optimising the demolition process, securing the supply chain and how we can produce the concrete elements at a competitive price. We have now achieved that goal.
A 23% REDUCTION IN CO₂
— The achieved reduction of 23% CO₂ compared to our standard concrete elements, where we have replaced concrete with the recycled concrete elements. If we look at the concrete mix and replace more cement in the concrete blend — for example with calcined clay — we see the potential for further savings in the CO₂ footprint, explains Camilla Dyring, Head of Sustainability at CRH Concrete.
— The recycling percentage is approximately 25% in the cast elements, states Vibeke Starup, Director of External Operations at CRH Concrete, and continues: We continuously work to optimise our concrete elements and are looking into various solutions for reducing CO₂ in our concrete elements. We can now deliver concrete walls with recycled concrete elements. I am very proud of this — and very much look forward to discussing this new opportunity with our customers.
Results
Approximately 25% recycling content in the newly cast elements. 23% CO₂ reduction compared to our standard concrete elements, and 37% CO₂ reduction compared to the generic data basis for concrete elements in BR18 Annex 2, Table 7.
Calculation of the CO₂ reduction: Until we have a better data basis, the recycled concrete pieces are calculated using the same emission data set as crushed concrete.
