Rheological Characterization of Bituminous Binder containing Wax based Warm Mix Asphalt Additive

Warm mix asphalt (WMA) has been gaining increasing popularity in recent years due to energy savings and environmental benefits. The mechanism of WMA is to use some additives or technologies to reduce the viscosity of bitumen and to modify the rheological behavior of bituminous binders, and thus improve the workability of the mixture at lower temperature. In this study a paraffin wax based additive Sasobit is used to reduce the viscosity and thus mixing and compaction temperature during hot mix asphalt production. VG 30 grade bitumen binder is used in the present study. Sasobit is added in the dose of 2 percent, 3 percent and 4 percent by weight of binder. Brookfield viscometer is used to determine the viscosity of the binders with and without sasobit at test temperature of 90, 120, 150 and 180 O C. Dynamic Shear Rheometer is used to study the Rheological behavior of the modified n unmodified binders. The study shows that the mixing, laying and compaction temperatures can be reduced considerably when sasobit is added to the binder. Laying and compaction temperature can be as low as 80C with VG-30 bitumen when 4 percent sasobit is added and due to this there will be an overall reduction in quantity of emission of pollutants when the bituminous mix is made at this low temperature.