Under long-term loading, the mechanical properties of geogrids in eco-bag reinforced soil retaining walls (ERSW) gradually weaken due to creep and photo-oxidative aging. In contrast, the continuously growing roots transfer their tensile strength to soil shear strength. However, the reinforcing effect of plant roots within retaining walls is often overlooked in current research and design. This study investigated the reinforcement effect of plant roots and geogrids on ERSW stability through theoretical derivations using the Swedish circle method for roots penetrating potential sliding surface and two-wedge method for shallow roots. The results showed that their synergistic reinforcement effect affords the highest overall stability of ERSW under loading. Additionally, the compensation ability of roots was investigated by vertically loading a scaled ERSW model with palm leaves and designing 16 sets of controlled tests with two geogrid lengths, three geogrid spacings, and four root lengths. The horizontal displacement of the facing, horizontal earth pressure behind the eco-bags, and geogrid tensile strain under various conditions decrease by 5.47%, 3.71%, and 4.17%, respectively, with increases in the unit length of the geogrid, and by 3.625%, 1.411%, and 4.713%, respectively, with increases in the unit length of roots. In the three parameters, the compensation rates of the root for the geogrid length are 0.66, 0.38, and 1.13, respectively. The reduction rates of the three parameters are 34.38%, 45.26%, and 58.62% with the geogrid spacing decreasing from 30 cm to 20 cm under the no-root condition, and the rates change to 56.25%, 21.14%, and 63.22% with a geogrid spacing of 30 cm and the addition of 15 cm long roots, respectively. In the three parameters, the compensation rates of 15 cm length roots for the geogrid spacing are 1.64, 0.47, and 1.08, respectively. Therefore, roots provide a compensatory effect on geogrid strength, enhancing the long-term stability of ERSW.

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 mu m (the main share is made up of bitumen microdroplets with a diameter of 2-4.5 mu m). 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.