Recycling of reclaimed asphalt from porous asphalt

High requirements are placed on the recycling of reclaimed asphalt in Germany based on EN 13108-8; these are formulated in the technical rules for asphalt road construction. Technical rules describe the criteria which need to be fulfilled to prove the suitability of the reclaimed asphalt. The main focus of proof refers to the suitability of the bitumen contained in the reclaimed asphalt. It is generally assumed here that the softening point must not exceed a maximum value of 77degreesC and a mean value of 70degrees. In the event of higher values excessive aging of the bitumen is assumed. The special bitumen that are used in Germany for porous asphalt already have softening points RuK of at least 65degrees on delivery due to the high proportion of polymer. When reclaiming is carried out after approximately 10 years, these parameters are increased between 80 and 90degrees. Thereport describes the suitability of reclaimed asphalt made from porous asphalt with such kinds of bitumen. It describes steps that lead to the use in asphalt intermediate layers. Amongst other things the force ductility, the elastic recovery and further parameters with the aid of the dynamic shear rheometer and the bending beam rheometer were determined on the bitumen of the reclaimed asphalt as well as on the resulting asphalt mix. Furthermore on the resulting asphalt mix rut tests were realised to evaluate theresistance against deformation, tensile tests and cooling tests were carried out to determine the low temperature behaviour. For the covering abstract see ITRD E157233