Удосконалення методу оцінки стійкості покриття нежорсткого дорожнього одягу до утворення колії

Abstract

Introduction. The experience of road operations of recent years shows that one of the most common defects in asphalt pavement under the impact of traffic loads and high summer temperatures is rutting which leads to decrease of its life time and, respectively, the road pavement design as the whole. The need to improve the method of evaluation of stability of non-rigid pavement against the rutting is determined. Problem statement. Taking into account that non-rigid pavement is in complicated operational conditions (it is confirmed by intensive growth of defects, such as rutting) due to increase of traffic loads and high summer temperatures, it is needed to increase the stability of non-rigid pavement against rutting. Purpose. Purpose is to improve the method of assessing the stability of the non-rigid asphalt pavement against rutting under the impact of vertical loads of vehicles at high summer temperatures. Materials and methods. Methods of research are analytical and experimental using the provisions of the theory of elastic plasticity and thermal elasticity and experimental methods of studying the rutting formation in non-rigid asphalt pavement; methods of numerical simulation; methods of mathematical statistics. Results. On the basis of the performed analysis, the working conditions of non-rigid pavements were considered, as well as the existing theoretical and experimental methods of forecasting the rutting formation was analyzed. Analytical dependency is achieved and method of evaluation the stability of non-rigid pavement against rutting under the impact of vertical vehicle loads is improved that allow considering the complex impact of major factors, namely: thermo viscous elastic properties of asphalt, soil stabilization, asphalt temperature, vertical pressure on pavement of vehicle tires, intention of vertical pressure, time of load impact. The calculated thermoreological characteristics of asphalt concrete and reinforced soils, the adhesion strength between asphalt and the foundation during shearing were experimentally researched. Field, laboratory and bench tests of the impact of various factors on the formation of residual strains in the form of rut were carried out, as well as the regularities of impact of influence factors on the intensity of the rutting formation in non-rigid asphalt pavement. Conclusion. During work, the method of evaluation of the stability of the non-rigid pavement against the rutting was improved and the complex impact of the main factors was considered, namely: thermo viscous elastic properties of asphalt concrete, vertical pressure of vehicles on the pavement and the time of its impact on the structure; the intensity of vertical loadings. The results of research were used in the development of regulations for the design, construction, reconstruction, repair and operation of asphalt pavements on highways of Ukraine.