Streets of Tahkokangas, Oulu

Concrete from buildings demolished on-site was used for pedestrian and cycling routes, beneath ski trail foundations and in the parking area. The crushed concrete was produced directly on the construction site, resulting in very low transportation volumes. According to our circular economy assessment, using crushed concrete generated from the demolition works directly in the project is more economical and environmentally friendly than using industrially manufactured crushed concrete. If all streets had been built using the concrete aggregate produced on-site, emission reductions of 40% and cost savings of 20% could have been achieved. The Tahkokangas area is being planned to accommodate predominantly low-rise housing and apartment buildings, along with services for approximately 2,200 future residents. The zoning supports circular economy-based construction and the use of demolition waste in substructures. The area includes roughly 3 kilometres of routes for walking and cycling, a parking area and a 1.3‑kilometre fitness trail, all of which make extensive use of recycled materials. In the street structures, industrial by‑products such as OKTO insulation were used alongside natural materials. Although the construction products were transported from Tornio to Tahkokangas, their emissions remained lower than those of natural sand because the material’s insulating capacity reduced the need for excavation and the total volume of materials. The use of insulation achieved a 10% reduction in emissions and a 15% cost saving. According to the calculations in our circular economy assessment, the higher the street structure class or the thicker the structural layers, the greater the emission and cost savings.