Increasing the level of aging stability of bitumes modified by kaolinite

During the literature review analysis, the main causes of bitumen binders aging were identified and the kaolinite modifier was proposed that have increased the bitumen aging resistance. The physical and mechanical properties of bitumen modified by kaolinite for the following indicators were studied: penetration at 25 °C, softening point, ductility at 0 °С, Fraas brittle point, dynamic viscosity at 105 °C, 135 °C and 165 °C. The bituminous binder aging was simulated in an RTFOT oven. The aging quality was determined by the softening point change, after aging in the RTFOT oven. The possibility of short-term aging reducing of modified bitumen at a kaolinite content of 2 % to 8 % by 12.5–28.6 % has been established. The characteristic peaks of bituminous binder aging: 1738, 1640, 1654, 1217, 1033 cm^-1 were revealed by the IR spectroscopy method. It was established that the kaolinite introduction into bitumen has caused a significant decrease of aging processes, which has confirmed by the IR spectroscopy data: the peaks at 1640, 1564 and 1217 cm^-1 almost completely have disappeared in the difference spectrum, and the intensity of carbonyl absorption band at 1738 cm^-1 has decreased. The obtained experimental data confirmed the similarity of the processes described in previously published studies of other authors and the continuing research prospects in the direction of increasing the bitumen binders aging resistance at searching for new modifiers types and determining them optimal quantities.