Calculated purpose of the distance between the expansion joints of cement concrete pavements of roads

Problem. The article discusses current issues of increasing the efficiency and quality of construction of cement concrete pavements for highways. It is shown that the regulatory documents in force in Ukraine recommend reducing the distances between compression joints and expansion joints during the construction of roads made of cement concrete. However, such a reduction leads to a slowdown in the pace of road construction and a significant increase in construction costs. The increase in cost occurs due to frequent stoppages of a set of concrete-laying machines and the formation of a large amount of concrete waste. The cost of this waste can reach UAH 200 thousand per 1 kilometer of road. In addition, frequent stops of a set of machines when laying cement concrete pavements of highways slow down the time it takes to put roads into operation. Purpose of the work. The aim is to calculate the expansion of cement concrete pavement when heated under operating conditions. Methodology. The work used formulas for thermophysical calculations during thermal expansion of concrete. The paper presents the results of thermophysical calculations of the expansion of cement concrete pavements of highways during their operation at elevated temperatures. It has been shown that when there are a large number of compression joints, they can partially compensate for the space required for concrete expansion. At the same time, they can act as compression joints during low temperatures. A design of double expansion seams has been proposed, which allows increasing the distance between them. The joint work of compression and expansion seams makes it possible to increase the distance between expansion seams. Due to this, it is possible to reduce their number, while simultaneously increasing the speed of construction and maintaining the quality indicators of the coating concrete. Originality: The article presents the results of a production test of thermophysical calculations. It is shown that two experimental sections of road surfaces were built. The concept of the maximum value of thermal expansion of concrete was further developed. Practical value: On one of them, the distance between expansion joints was 101 m, and on the other – about 300 meters. In this case, the distance between the expansion joints in the double seam was 1.5 meters. These parameters were sufficient for efficient and high-quality operation of double expansion joints.