Analysis of climatic zones in Poland with regard to asphalt performance grading

Towards the end of the last century a new system of bitumen grading was developed and implemented as part of the American Strategic Highway Research Program (SHRP). Its aim was to better adjust the testing methods and requirements for road bitumens to the actual conditions in which those bitumens serve in road pavements. Currently in Poland, similarly as in the other EU countries, road bitumens are tested and classified with regard to mainly the penetration value determined at the temperature of 25°C. It should be noted that this classification is not correlated with the climatic conditions in which the bitumens are to serve in the road pavement. This paper presents the results of analyses concerning the determination of the temperatures at which bituminous binders serve in the Polish climatic conditions. A division of the area of Poland into climatic zones depending on the required performance grades (PGs) determined for bitumens on the basis of climatic data from 61 meteorological stations for a period of minimum 20 years is presented. It is proposed to select bitumens depending on the climatic zone in Poland, taking into account the proper probability level which follows from the road class.