Effects of a surfactant-wax based warm additive on high temperature rheological properties of asphalt binders

Abstract

Asphalt binders and mixtures are more susceptible to permanent deformation at high temperature. The Dynamic Shear Rheometer (DSR) test results have been extensively used to evaluate the effects of wax and foamed warm additives on asphalt binder properties at elevated temperature. Wax based additives improve the rheological properties of the binders at high temperatures, while foamed based additives exhibit no significant effects on binder rheology. However, the literature reports contradictory effects of surfactant-wax warm additive named Rediset, on binders and mixtures propertiesat high temperatures. Some studies reported positive effects, while others found otherwise. This paper evaluates the effects of binder type, additive content and loading type on high temperature properties of warm asphalt binders incorporating Rediset on temperature, strain, frequency and stress sweep tests as well as flow, creep, multiple stress creep and recovery and zero shear viscosity test results. The results showed that the effects of Rediset depended on binder type, additive content and loading type. It implies that the chemical composition of different dosage of this warm additive with various binder types, directly affect the performance of binders subjected to various loading types at high temperatures. Hence, simply relying on one type of shear loading in the DSR test for evaluating the high temperature properties of binders incorporating a surfactant-wax additive, can lead to erroneous conclusions.