Оцінка довговічності цементобетонного покриття автомобільних доріг

Abstract

Introduction. In recent years, around the world on highways, there is a tendency to increase vehicle intensity and increase the share of heavy cars and multistage of trains with increased pressure in pneumatization. This causes premature destruction and invalid deformation on the roads, rapid withdrawal of their failure, a significant increase in the cost of transportation. The partial solution to this problem may be the use of cement concrete to cover the highways. In many countries, cement-concrete roads occupy a significant share. China, the world leader in the production of cement concrete, annually erected 20 thousand km2. KM high-speed cement-concrete roads. In the United States the share of cement concrete roads is 60 %, Germany ― 42%, Czech Republic ― 22 %, but in Ukraine ― only 1 %. Problem Statement. To date, existing methods and criteria for assessing the durability of the cement-concrete covering are disparate and as in assessing crack resistance coverage is taken into account separately or only the action of vehicles or the effect of temperature changes. Consideration of the common impact of temperature changes and the action of pneumatic wheels of vehicles, as well as shrinkage of cement in the estimation of crack resistance coverage will allow more objectively assess durability. The formation of cracks in the cement concrete coating violate the integrity and monolithic road construction, sharing it to separate blocks, unrelated to each other, the number and length of the formed cracks, formed on the coating, almost do not affect the movement of cars until the resulting pothole and chipping, which leads to deteriorating coverage, lowering the level of traffic safety and creating emergency-hazardous situations. As a consequence, the cost of maintenance and repair of cement concrete covering of highways, which are subjected to premature destruction, increases. Purpose. The purpose of this work is to develop a method estimation durability of cement concrete covering roads, taking into account the common influence of shrinkage, temperature changes and the actions of pneumatic wheels of vehicles. Materials and methods. Analysis of scientific publications, technical and normative literature on estimation of durability of cement concrete covering of roads. Results and conclusions. Received dependencies that allow to calculate the service life of the projected cement-concrete pavement on highways crack resistance taking into account the common effects of shrinkage, temperature changes and the actions of pneumatic wheels of vehicles.