Rheological behaviour of n-alkane modified bitumen in aspect of Warm Mix Asphalt technology

It can be found that based on the comparison of the viscosity curves for neat bitumen and bitumen modified with n-alkane additives, it is possible to make first selection of the optimal additive in aspect of the WMA technology. Based on the viscosity curve analysis, for the WMA technology effective additives should present melting temperature in the range of temperature between 90 °C and 130 °C. At this temperature, n-alkane modified bitumen should be more viscosity susceptible, which mean that viscosity should faster decrease with the temperature change, as compared to the neat bitumen. Based on the rheological and morphological assessment, it can be stated that too high melting point of n-alkane additives generate some problem with additive dissolving and homogeneity of binder and does not compensate beneficial changes in bitumen rheological properties.