ABSTRACT
ABSTRACT: In Norway, recycled concrete aggregates were introduced in design codes for road construction in 2005, including material specifications. Until then, utilisation of these materials was limited due to the fact that the mechanical properties of aggregates in many cases did not comply with the specifications concerning mechanical strength. However, a number of field projects have revealed good functional properties (proven suitability), showing that traditional test methods for mechanical properties are clearly not suitable for this kind of materials. A proper evaluation should be based on performance-related (functional) tests. The paper discusses some of these field-lab contradictions with reference to a field trial at highway E6 south of Trondheim where recycled crushed concrete aggregates (RCA) has been used as sub-base layer since 2003 in a pavement designed for rather heavy traffic (Annual Daily Traffic > 10000). Several field and laboratory tests were conducted before, during and after construction. Since then the structural performance and the surface characteristics have been followed up frequently. The registrations so far show very promising results. The project has given valuable inputs to Norwegian pavement design standards and has already encouraged further use of recycled/ secondary materials in Norway.
