Crushed asphalt, also known as KAS, consists of asphalt that has been crushed to the fraction 0-16 mm. Crushed asphalt is suitable for subgrade protection and base layers for, among other things, road construction, cycle paths, pavements and paths, and parking lots. Crushed asphalt 0-16 (KAS) at Blue Phoenix is produced in accordance with the Danish Road Directorate's current guidelines for materials.
Download the Norwegian Road Directorate's construction guide for the material.
Crushed asphalt, an attractive recovery material made from used asphalt from roads and paths, is a good choice as e.g. bottom protection and bearing layer in a number of construction projects. As a construction material, crushed asphalt is not only economically advantageous, but also a more environmentally friendly solution that reduces the need for new raw materials and recycles waste.
Applications for crushed asphalt
Crushed asphalt is in many cases a good substitute for traditional stable gravel, sand or stone and is widely used in construction work, including as bottom protection or support layer in road grades or red and cable trenches. The material's properties also make it suitable for repairing existing asphalt surfaces, where it can effectively fill holes and cracks, ensure an even surface and extend the life of roads and paths. Crushed asphalt can in several cases also be used in new asphalt production and thus recycled.
Crushed asphalt (KAS) at Blue Phoenix
Crushed asphalt (KAS) consists of min. 95% crushed asphalt. KAS is produced in two fractions 0-32 mm and 0-16 mm. Crushed asphalt (KAS) is intended to be used as an unbound base layer in roads and squares and for the rehabilitation of cable trenches instead of stable gravel.
KAS has a carrying capacity which is slightly less than the carrying capacity of stabilized gravel. KAS can be used in light traffic, corresponding to traffic class T0-T2. KAS mainly consists of crushed asphalt and therefore cannot be expected to be dimensionally stable under static loads.
KAS 0-32 mm has a grain curve that resembles the grain curve for stable gravel. As stable gravel, KAS 0-16 mm has a well-graded grain curve, although the maximum grain size (D) is 16 mm instead of 32 mm. In crushed asphalt, all particles are crushed, therefore it can also be experienced that it requires slightly more energy to incorporate KAS compared to stable gravel.
The installation of KAS is carried out as when installing stable gravel. It is recommended to install it at a water content of 2-4% points above the optimal water content, as KAS normally has a very low filler content and therefore does not hold water. KAS from Blue Phoenix is recommended to be installed so that the compaction requirements given in AAB for unbound base layers of crushed asphalt and concrete are met. In AAB for unbound base layers of crushed asphalt and concrete it is stated that the water content determined with the isotope probe must be corrected by 4,5% points for KAS.
KAS may contain a small amount of crushed concrete, brick, glass, metal, wood, plastic, etc. We always encourage dialogue with the authorities before using crushed asphalt in building and construction projects.
