Research of influence of adhesive additives on physical and chemical properties of road bitumens

To increase the adhesion strength (wetting ability) of bitumen, and, consequently, reduce the likelihood of premature occurrence of defects formed on asphalt concrete coatings, it is necessary to use various kinds of surfactants that increase the adhesion ability of bitumen. Adhesive additives to road bitumens increase the mobility of the organic binder, help reduce the number of uncoated grains of mineral material, which facilitates the compaction of asphalt concrete mix. One of the problems of durability of asphalt concrete pavements is the lack of strong adhesion of the bitumen film to the surface of the mineral material. To increase this strength, various adhesive additives are used, which affect not only the adhesive properties of bitumen, but also its physical and chemical properties. The main task of the work is aimed at solving the issues of the influence of adhesive additives on the physicochemical properties of organic binders used in road construction. The quality assessment of the modified bitumen was carried out according to GOST 22245-90, which, at present, is guided by the selection of the composition of the asphalt concrete mixture. As a result of the study, effective adhesive additives were identified that contribute to the minimal change in the physicochemical properties of viscous road bitumen and possess thermal stability under prolonged exposure to elevated temperatures. Studies have shown that almost all adhesive additives not only improve the adhesive properties of organic binders to mineral materials, but also can alter and even worsen the physicochemical properties of the original organic binder, which can adversely affect the properties of asphalt concrete. The study used the original bitumen from only one manufacturer and the negative effect of adhesive additives may be due to the incompatible chemical composition of the adhesive additive with the group composition of bitumen and the mineralogical composition of the mineral material.