Study of physical and rheological properties of wax modified binders using classic and SHRP testing methods

Abstract

Considerable effect of Fischer-Tropsch (FT) paraffin on improving the original asphalt properties along with reducing the emissions and saving energy, encouraged using this additive as an effective modifier. In this study, extensive laboratory investigations have been carried out using classic and SHRP testing methods. The results of both test methods show that adding FT paraffin into original asphalt reduce penetration, ductility at 15°C, and <i style="mso-bidi-font-style:normal">m</i>-value, while enhance penetration index, softening point and creep stiffness. Results indicate that there is an inflection point or inflection interval in ductility at 5°C. Rheological properties of modified specimens are investigated with DSR in temperature sweep and creep tests. Results indicate that the aforementioned parameters increase by increasing the FT paraffin content. Furthermore, at higher temperatures , increasing the FT paraffin additives content can reduce the binder viscosity and at lower temperatures less than the melting point of FT paraffin the reverse is true.