Binder design for asphalt roads – Definition of a chemical rheological requirements profile
Among other factors, the durability of asphalt roads depends on the bitumen used. The properties of the binder, in turn, are influenced by its chemical composition and structural make-up. Against this background, the Federal Highway Research Institute (BASt) commissioned the Institute of Civil Engineering at the Technical University of Berlin with fundamental work on the characterisation of various bitumens. The relationships between the chemistry of the binder and its behaviour in terms of rheology, ageing and adhesion were to be examined in this context. The objective was to derive a binder design with which bitumen properties can be specifically influenced.
The present fundamental research confirms that some essential physical properties of bitumen can, in principle, be calculated on the basis of the chemical composition. The derivation of the basic equation, with the help of which it is possible to describe various chemical-physical relationships, can be regarded to be of particular value. By the applied method existing test procedures can be experimentally and statistically validated with regards to their significance.