The object of research is to determine the optimal modes of asphalt-concrete mixture. Method. The thermal fluctuation theory of strength for calculating durability and determining the optimal modes of asphalt concrete mixture preparation as a research method shows that the use of "silos-thermostats" contributes to achieving the highest possible strength of asphalt concrete. Results. Consequently, it has been proved that the tested methods of determining the quality of road bitumen can be used as a basis for a new instrumental base for evaluating its adhesive properties. In this regard, the quality of road surfaces can be improved at no additional cost.