Investigating cohesive healing of asphalt binders by means of a dissipated energy approach

The paper reports the results of an experimental investigation in which the cohesive healing properties of different types of asphalt binder were evaluated by means of the dissipated energy ratio approach. A specifically designed testing methodology was proposed which involves comparing the response of binders subjected to continuous oscillatory shear loading carried out without rest periods and with single rest periods introduced at predefined levels of damage A rheological parameter (Healing Ratio) was introduced to quantify the magnitude of healing occurring during rest time and to rank the consequent healing potential of binders. Obtained results indicate that the investigated binders did not completely recover their original fatigue resistance after rest time, confirming the existence of some intrinsic irreversible damage, the amount of which depends on the total damage experienced before load removal. Experimental results also indicate that healing performance of binders can be significantly enhanced by polymer modification.