The individual components‘ influence on aging of bitumen mineral materials

When heating bitumen-mineral mixtures at high temperatures under the air access conditions, their accelerated aging is observed, i.e. the values and quality indicators‘ decrease of the compacted samples from them. Due to the different structure of bitumen films on the mineral components‘ surfaces of different compositions and sizes, aging processes may occur in different ways. In this regard, a need for a differentiated study of the aging process on the surfaces of large fine aggregates and the crushed part of the bitumen-mineral (asphalt concrete) mixture arose. The experiments in laboratory conditions are carried out according to the Volga State Technological University developed at the Department of Construction Technologies and Automobiles (according to RF patent No. 2654954). The aging processes analysis of the samples from bitumen-mineral mixtures is carried out using the dimensionless aging coefficient in terms of the ultimate compressive strength at +50 °C. The nature and dynamics of the samples‘ aging over time are assessed using special indicators - the aging coefficient and the aging intensity. As a result of the experimental study, the optimal ratios of bitumen with mineral components, taking into account their susceptibility to aging over time, were established. The changes‘ dynamics in the bitumen aging intensity in time in the bitumen-mineral mixture as a whole and separately on the mineral components‘ surfaces separately has been studied. The results of this study can be taken into account when revising the standard service life values of the roads with structural layers of bitumen-mineral materials.