Selection of type of warm mix asphalt additive based on the rheological properties of asphalt binders

This paper presents a methodology to characterize the changes in the rheological properties of unaged and aged asphalt binders incorporating various Sasobit (R) and Rediset (R) contents at high and intermediate temperatures. The changes in the rheological properties of asphalt binders per 1% Sasobit (R) and Rediset (R) contents were measured using new proposed parameters namely the non-dimensional viscosity index (del eta(s)), gradients of the Superpave (TM) rutting factor (del NSRP) and relative G*sin (delta) (del RG). The results of del eta(s) showed that although both additives reduce binders' viscosities, the decrease per 1% additive depends on test temperature, aging state, asphalt and additive type. The results of flow test also showed that Rediset (R) does not change the Newtonian behavior of asphalt binder, while Sasobit (R) converts the Newtonian flow into non-Newtonian at some specific shear rates, which this effect was defined in terms of threshold of non-Newtonian flow (TNF). Based on the results of the rheological binder tests, three viable scenarios to select Sasobit (R) or Rediset (R) based on the sustainability and structural performance were introduced (C) 2015 Elsevier Ltd. All rights reserved.