THE EFFECT OF BITUMEN TYPE ON THE ASPHALT MIX RESISTANCE TO RUTTING

The paper presents research results showing the influence of bitumen type (BIT 60, PmB 50-90, PmB 45) on the asphalt mix resistance to rutting. Laboratory studies were carried out for each bitumen type for three asphalt mixes of previously defined composition. The patterns of each respective series have constant volume concentrations of all components that differ according to the properties of dosaged bitumen. After analysis of measurement results regarding rutting depth and rutting rate, conclusions were made about the effect of bitumen type on rutting. There is an inversely proportional relationship between the rutting and viscosity of bitumen in asphalt at standard temperature at which the rutting was analyzed. The relationship proved to be linear provided that bitumen viscosity was expressed by its logarithm.