Concrete Recycling : Innovation Promises Complete Recyclability of Concrete

Sika -a specialty chemicals company with a leading position in the development and production of systems and products for bonding, sealing, damping, reinforcing, and protecting in the building sector and motor vehicle industry- has developed a new, ground-breaking recycling process for old concrete.

The old concrete is broken down into individual parts gravel, sand and limestone in a simple and efficient process, which also binds about 60 kg of CO2 per ton of crushed concrete demolition waste. This innovation - with the brand name «reCO2ver» - will make a significant contribution to reduce the ecological footprint of the construction industry.

With the new process, old concrete can be completely recycled and saved from landfill. So far, attempts to recycle old concrete have led to rather low recycling rates, and only 30% of primary material can be substituted by these recycled materials in structural concrete.

According to the European Commission, 25–30% of all waste generated in the EU consists of construction demolition waste materials, many of which could be recycled. Recycling these materials is particularly crucial in dense urban areas, as this is where most old concrete accumulates.

Sika has succeeded in developing a highly efficient process that will allow to separate and reuse the components of old concrete as well as increase the recycled aggregates' quality.

Comparative testing of the Sika «reCO2ver» process has demonstrated that new concrete containing recycled content performs similarly to an all-new product. The Sika innovation will produce high-performance concrete while sequestering a significant amount of CO2.

Further process optimizations can be achieved, such as the flexibility to tailor specific concrete functionalities, with addition of other developed chemical additives.

Paul Schuler, CEO: “In the five largest EU countries alone, roughly 300 million tons of old concrete are generated every year. With complete recycling of these materials, up to 15 million tons of CO2 emissions can be captured. We are convinced that our new process has the potential to benefit both our customers and the environment.”

Frank Hoefflin, Chief Technology Officer, states: “With our strong expertise in concrete technology, we were able to develop a completely new recycling process that can be considered a game changer in the concrete industry. We are already developing complementary chemical additives and quality enhancers and are pushing the industrialization of our new technology.”