In accordance with new European standards, the Danish Road Institute has published four new Tender and Construction Precepts for materials that can be recycled. These apply to materials that can be used for unbound basecourses (crushed concrete, crushed bricks and crushed asphalt) and for municipal waste incinerator ash (MSWI) bottom ash), which can be used as subbase. Crushed concrete of three quality classes can replace granular unbound base material for all types of road. Crushed asphalt can be used as an unbound base material in all types of roads. Crushed bricks can replace granular unbound base material on roads, paths and squares with limited traffic. MSWI bottom ash has a slightly lower bearing capacity and does not drain as well as traditional subbase materials. It should not be used on heavily trafficked roads and there are restrictions as to its use when the subgrade is exposed to water. Ordinary environmental and work regulations apply for construction work using the recycled materials. The recycled material is suitable for smaller new constructions at a local level.
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