In any city, the construction and maintenance of the roads has a high environmental impact. This mainly comes from the production and transportation of concrete materials like paving stones and tiles. The cement and concrete industry is the world’s third largest emitter of CO2 and of other forms of industrial air pollution like nitrogen oxides (NOx).
To reduce the environmental impact of road construction, the municipality of Amsterdam wants to make re-use of pavement stones the new standard. This means that, when a street needs to be repaved, the old/used concrete tiles will be taken out, cleaned and recoated on location, and then simply applied again. Preliminary calculations suggest that such a re-use scenario yields 80% CO2 reduction compared to conventional replacement with new tiles and recycling of the old ones. Accordingly, re-using concrete pavers is crucial for reaching the city’s policy goals in circularity (use 50% less primary raw materials by 2030) and climate change (cut CO2 emissions by 55% in 2030).
“For energy-intensive products, like concrete pavers, re-using the product has much more impact than recycling. This is the way forward. In fact, we have to consider circularity in the infra sector, if we want to reach our climate goals.”
Joppe van Driel
Program Developer Circularity in Urban Regions
How much impact can we make? In this project AMS Institute and TNO will quantify the exact contribution to climate policy goals of different circular scenario’s:
(a) paving a street by re-using existing concrete pavers;
(b) putting in new pavers while recycling the existing pavers into granulate;
(c) replacing the existing pavers with a new sustainable paving material (for example biobased concrete or geopolymer concrete).
We will compare the impact of these three scenario’s on pollution, CO2 emission, use of primary raw materials and climate resilience. This way, the asset managers can take the sustainability of the materials into account when planning, budgeting and executing paving projects – based on hard data and scientific insights.
This research serves as a scientific basis for optimizing road construction & maintenance measures within the asset ‘Paving materials’ in the Municipality of Amsterdam. Moving beyond modelling using key figures from literature, we will base the calculations on local data from the city and its contractors. Along with the hard data, we will provide impact analyses of different upscaling scenario’s for the city of Amsterdam. We will also produce a widely accessible publication, Circular paving of cities, in which the results of the research will be visualized and described in an accessible and interactive way. This way the asset managers can take the sustainability of the materials used into account when planning, budgeting and implementing paving projects in the city.
|Also involved in the development of this program:||