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Introduction. The use of bitumen microdispersed emulsion as a resource-saving method for road surface construction is a popular trend in the development of innovative nanostructures. The technological use of petroleum bitumen as a binder for road materials requires a reduction in rheological viscosity. This can be achieved through synergistic developments that involve the use of various additives and modifiers. Methods and materials. The composition of bitumen microheterogeneous emulsions includes: bitumen-containing raw materials (up to 70–80% of mass); water with hardness up to 6 mg-eq/l (from 20 to 30%); emulsifiers (up to 3%) and other components. For large-tonnage production of water- bitumen emulsions, a colloid mill is the most technologically advanced equipment. Results. Water-bitumen emulsions are formed as a result of two competing processes: crushing (dispersion) and coalescence (merging) of microdroplets of the bitumen dispersed phase. The microheterogeneous bitumen phase is distributed in the aqueous dispersion medium in the form of microdroplets ranging in size from 1 to 10 μm (the main share is made up of bitumen microdroplets with a diameter of 2–4.5 μm). The synergetic durable microstructure of asphalt concrete road surfaces, which is formed by supplementing interaction in the boundary layers of the bitumen binder with the surface of the mineral component, is determined by the dominant interaction of complementary factors. Discussion. The synergetic approach to extending the service life of asphalt concrete road surfaces by using bitumen microdispersed emulsions holds promise for interpreting their evolution. The road construction industry of the Russian Federation at the beginning of the 21st century is characterized by a large-scale revision of regulatory documents, regulating the requirements for the construction and operation of highways. Conclusion. The optimal solution to the current problems of intensive construction and reconstruction of Russian highways is the improvement of technological characteristics of road surfaces by adding bitumen microdispersed emulsions to the composition. In complementary strengthening of weak soils of the road surface of high-speed highways, the use of water-bitumen microdispersed emulsions is also recommended.

ABSTRACT: Introduction. The issue of enhancing the long-term performance of asphalt concrete pavement on highways is not entirely addressed by conventional solutions, such as improving the choice of material composition and refining the production process for bitumen binders and mineral filler compounds. One of the most promising ways to improve the performance and durability of asphalt concrete is the complementary modification of bitumen and road-concrete nanocompositions with thermoplastic and elastic polymers. Methods and materials. Bitumen binders are assessed employing suitable methodologies to determine the following technological parameters: extensibility, softening temperature, brittleness, elasticity, and so forth. Asphaltenes of bitumen binders are the most important structure-forming component and form associated nanoclusters with sizes of 15–200 nm. Thermoplastic block copolymers are introduced into the composition of bitumen binders in granular form (chips) or melted form. Additionally, compatibilizers are used to improve the compatibility of complementary copolymers in bitumen binders. The quality of the finished asphalt concrete composition is significantly affected by the characteristics of the main components: mineral powder, sand, crushed stone, bitumen binder and macromolecular nano-additives, as well as by optimal process modes: mixing temperature, etc. Results. The complementary interaction of supramolecular associations of asphaltenes and fragments of macromolecules of polymer nanocomposites ensures the formation of Van der Waals bonds due to spatial mutual correspondence. The introduction of polymer nanomodifiers leads to an increase in the softening temperature and a decrease in the brittleness temperature of bitumen binders due to the formation of sufficiently stable supramolecular complexes. Discussion. Synergistic nanoadditives of complementary macromolecules into the bitumen binder provides a fewfold increase in the adhesion of the bitumen composition and the mineral components, as well as a noticeable increase of the temperature range for plasticity and deformability. Asphalt concrete coatings with polymer-bitumen binders increase the operability of the roadway and resistance to the formation of plastic flow deformations (shifts, ruts) at high and low temperatures. Conclusion. Bitumen binders of asphalt road concrete, which have been modified with polymer nanocomposites, have higher adhesion, an extended range of thermoplasticity and water resistance