Abstract
Slopes of road subbase and subgrade under operation are subjected to deformation and destruction while being affected by atmospheric precipitation, deicing agents and temperature drops. Stabilization of road slopes should proceed throughout the entire life cycle of the road. There arose a need to work out the most effective and durable design solution. Structures being under operation are exposed to external factors that cause washouts and defects of expansion joints. Washouts of geocell reinforcement structures may occur as well. Structural repairs sometimes are not effective, so destructions continue and progress. Analysis of the use of conventional technologies has shown that implementation of a polyurethane binder for stabilization of slopes is the most effective design solution under certain conditions. Binder based on polyurethane, when applied to rock material (crushed stone or gravel), forms a durable structure that is resistant to external influences and has high strength properties. A set of national standards for application of this technology is currently being developed. It is confirmed that the material under consideration meets the requirements of fire protection, sanitation and epidemiology, hygiene, and environmental safety. By these days, this technology has been implemented at more than 30 highway structures in the city of Moscow and in the Moscow and Smolensk Regions.
Highlights
The destruction happened after three heavy rainfalls as a consequence of a defect in the expansion joint
Binder based on polyurethane is a system of two liquid components which being mixed in a certain ratio and applied to rock material form a structure with high strength properties, durability, and resistance to external influences
According to the calculation results it is possible to predict the moment of reaching the permissible wear rate for the tested structure, which will come in 31 years after the start of service life
Summary
To increase the operating life of roads and highway structures and protect subgrades from negative external effects, which include atmospheric precipitates, influence of deicing agents, loads from vehicles, temperature drops, insolation, and vandalism, the improvement of stability of subgrade slopes is required.Stabilization of subgrade slopes is carried out at all stages of the lifecycle of highways and highway structures, specifically during construction, roadway replacement, road repair and maintenance [1].Conventional technologies of subgrade stabilization include the following: • stabilizing with soil and grassing; • stabilizing with crashed stone or gravel (riprap); • the use of gabion “Reno” mattresses; https://doi.org/10.1051/e3sconf/202124404012• the use of three-dimensional geosynthetic structures filled with soil or crashed stone;• stabilizing with solid or prefabricated reinforced concrete structures. Consolidated experience of operating subgrades educed several problems. For instance, Figure 1a shows a washout of the slope cone stabilization structure, which exposed the abutment piles. The destruction happened after three heavy rainfalls as a consequence of a defect in the expansion joint. As a result, all the water flows went down from the road surface to the abutment.
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