Changing of technical and operational road parameters caused by traffic load and climatic factors

Abstract

Climatic factors and car wheels are the reasons of changes in road condition: deformations of subgrade, cracks, potholes and rut appear, roughness and safety are deteriorating, and the strength of the road structure reduces. In our opinion, cracks in the road structure are of particular importance. The appearance of cracks causes the destruction of the whole road structure during the road operational cycle. There are many classifications of cracks depending on the reasons of their occurrence as well as repair methods of cracked asphalt pavements. The main reasons that contribute pavement cracking are: 1) horizontal tensile stresses caused by an unfree deformed pavement layers on a continuous and cracked subgrade owing to temperature changes, moving vehicles and the contraction due to the aging of asphalt mixtures; 2) transverse shear stresses in the vertical plane above the crack or joint in the base layer during the vehicles passing. We have carried out the research of the physical and mechanical properties and thermal properties of asphalt concretes, the research of the deflected mode of the pavement layers from different materials under the temperature and traffic loads using the finite element method. The results of the research on the experimental road in Pagiriai are of particular interest. These researches are original and they were carried out jointly with specialists of the Vilnius Gediminas Technical University. During the research the relation between the loading modes of the roads and an appearance of pavement damages was established, the most stable to the formation of damages road structures were revealed corresponding to climatic conditions and traffic load conditions. The mechanisms of cracking under current conditions were revealed according to the research results; the recommendations for the upper layer material choice and the choice of activities to repair the damages were formulated. These developments will improve the performance of the road and allow to do crack repair activities more effectively.