FORECASTING OF ROAD COVERING OPERATION TEMPERATURE REGIME OF KYIV-LVIV MOTORWAY

Abstract

Motorways technical condition is influenced by the temperature regime of road covering operation. At high road surface temperatures in the summer time, softening of asphalt concrete with the formation of ruttings and corrugations is observed. Low temperatures in winter cause asphalt concrete fragility, which contributes to the formation of potholes at heavy vehicles wheels dynamic action. In previous researches by the authors it is suggested to use probable monthly and annual durations of dangerously cold and dangerously hot periods as indicators of a temperature mode of road covering operation and technique for their definition was developed.  These indicators for the Kyiv-Lviv highway are established due to the data obtained from meteorological stations located alongside the road at a distance of up to 100 km from it. The initial data include the average monthly values and standards of soil surface temperature at 21 meteorological stations obtained according to the results of meteorological observations. The characteristics of bitumen used in manufacture of asphalt concrete for the upper layer of pavement are also taken into account. The results showed that use of bitumen modified with polymers reduces duration of the dangerously cold period by an average of 1.5 times, and dangerously hot - by 16 times compared to conventional petroleum bitumen. The origin of the change in temperature alongside the road enabled dividing it into two segments, each of which has monthly and total annual durations of dangerously cold and dangerously hot periods for road covering made using road bitumen of two types. The results of the study enable conducting monthly planning of automobile transportation considering the restrictions on heavy vehicles movement during dangerously cold and dangerously hot periods. This mode of road operation will minimize damage to road covering.