Within the construction industry, there is a growing understanding that the traditional linear model of ‘make, use, dispose’ is unsustainable. The sector must make the shift towards a fully functioning circular economy. Society must learn to keep resources in use for as long as possible, extract the maximum value from them while in use and then recover and regenerate materials at the end of their service life.
There’s considerable scope to follow the principles of the circular economy, particularly with materials like concrete or asphalt.
Roundabout thinking
The first principle of circular economic thinking is to design for longevity. The excellent durability of concrete supports this principle, with examples of structures lasting for many hundreds, even thousands of years. The material’s qualities help to reduce the maintenance required for a building or infrastructure asset, mitigating the need to use additional resources for repairs.
Circular economic thinking also includes designing for service. The inherent structural resilience of concrete provides the flexibility to extend the service life of a well-designed concrete frame building, allowing internal spaces to be reconfigured to meet the needs of future building users.
If a building or infrastructure asset is no longer required, concrete columns or beams can be reused in other structures. Concrete’s constituents can also be designed to be fully recovered and recycled into new concrete or aggregate.
Another tenet of circular economic thinking is to design materials for re-manufacture. Asphalt is a material that supports this principle because it can be 100% recycled as asphalt. We’re seeing increasing volumes of planings from the existing local and strategic road networks being recycled and re-used.
However, designing for longevity, service, reuse and recovery of concrete or asphalt will require us to have a better future understanding of a material’s performance characteristics, including detailed records of its constituents, traceability and quality. If it isn’t possible to obtain this information, the ability to re-use the material is undermined and part of its value lost.
Considering life span
To create a legacy of more materials that can be recovered from infrastructure assets and buildings where the service life can be extended, we need to embrace whole-life thinking and ensure there is accurate and detailed data about materials.
Currently, the best way to record this information is to fully embrace Building Information Modelling (BIM). BIM can aid our understanding of the whole life performance of a building or asset by providing a detailed record of a structure’s fabric and the traceability of individual materials.
Transition to a circular economy requires us to leave a legacy of durable materials that can extend the service life of assets and be re-used, recovered and recycled. Extracting the maximum value from materials and assets will be vital and the industry will need to be able to draw upon accurate, historic and digital data to make more informed decisions.
