Service behaviour of hot asphalt with asphalt granulate of different types and quantities and derivation of a simple performance criterion

Contact person: Daniela Breddemann, M.Sc. Sören Holzwarth, M.Sc.

Asphalt roads fulfil another important role in addition to their decisive contribution to infrastructure. Due to their composition of aggregate and petroleum-based binders, they represent a ‘storehouse’ for natural resources. The thermoplastic properties of asphalt make it a construction material that can be used permanently with a high degree of reutilisation.
As part of the circular economy, the conservation of natural resources and in an effort to mitigate the consequences of climate change, it is necessary to act in a resource-efficient manner and use building materials that are of high value in terms of durability, ease of repair and reusability or recyclability. Asphalt can be both recycled and reused. In the hierarchy of waste management (according to § 6 of the KrWG), reuse is the optimal utilisation after the avoidance of waste and by definition means the reuse of a material/product for the same purpose - in relation to asphalt, this means the use of asphalt granulate in the production of asphalt mixes.
Since 1982, the reuse of asphalt in Germany has developed well due to an increasing reuse rate. As of 2013, for example, the reuse rate is just under 90 %. Regulations exist to ensure the homogeneous properties of asphalt granulate and are intended to guarantee comparable properties to asphalt mixes made from primary construction materials. However, due to the lower quality requirements, reuse is currently mostly carried out in asphalt base courses. [German Asphalt Association, 2014]

The aim of this research project is to create a simple performance criterion for assessing the service behaviour of hot asphalt with asphalt granules. In this context, the possibility of indirect verification of double coating is also to be considered. Using two different asphalt granulates, which differ in terms of the hardness of the recovered binder, the influence of the type, quantity and mixing time on the asphalt performance of an AC 16 B asphalt binder course and an AC 22 T asphalt base course is to be investigated.
The aim is to achieve a performance approach that is as simple as possible, with which the service behaviour can be evaluated in sufficient depth and the homogenisation of the binder mixture can also be estimated.

Behaviour in use of hot asphalt   (185.1 kB)

Client:

Bundesanstalt für Straßenwesen (BASt)
FE-Nr: 07.0299/2018/LGB

Project partner:

Basalt Actien Gesellschaft, Köln