Laboratory Characterization of Asphalt Binders Containing a Chemical-Based Warm Mix Asphalt Additive

Abstract

Different technologies, namely foamed asphalt, synthetic waxes, zeolites, and chemical additives, are used to produce warm mix asphalt (WMA). This study was undertaken to evaluate the effect of using different amounts of an amine-based chemical WMA additive on the rheology, performance grade (PG), and moisture-induced damage potential of an asphalt binder (PG 58-28). Superpave specifications were used to evaluate the rheological properties and PG of the asphalt binder. Also, a mechanistic approach-based on the surface free energy (SFE) method was used to evaluate the moisture-induced damage potential of the asphalt binder combined with commonly used aggregates in an asphalt mix. It was found that the dynamic viscosity of the asphalt binder was not significantly affected after blending it with the WMA additive. It was also observed that the Superpave high-temperature PG and the rutting factor did not reduce by an increase in the WMA additive content. However, the continuous low-temperature PG of the asphalt binder decreased with an increase in the amount of WMA additive. Furthermore, it was found that the fatigue resistance increased after blending the binder with the WMA additive. The SFE results of the asphalt binder revealed that the WMA additive used in this study reduced the moisture-induced damage potential of the asphalt mixes. However, the extent of this improvement was found to largely depend on the aggregate type. The outcomes of this study are expected to help better understand the influence of amine-based chemical WMA additives on rheological and long-term performance of asphalt mix.

Rheological Behaviour of WMA-Modified Asphalt Binders with Crumb Rubber

“…Likewise, the addition of SBS and WMA significantly increases the stiffness and rutting resistance of the asphalt binder [ 40 , 42 ]. These additives also generate a potential increase in resistance to fatigue and temperature cracking [ 43 , 44 , 45 ]. Other research concluded that the addition of Sasobit decreased the viscosity of the asphalt binder and improved the rheological performance at high temperatures and low-temperature cracking of the aged binder [ 46 ].…”

Rheology of Virgin Asphalt Binder Combined with High Percentages of RAP Binder Rejuvenated with Waste Vegetable Oil

“…A lower viscosity enables the effective coating of aggregate and permits lower processing temperature to reduce energy requirements and emission of volatile organics. 26,27 As shown in Figure 1, the viscosity measurements displayed considerable dependence on composition and a typical trend in viscosity with temperature. Addition of the RAP binder to the virgin binder increases the viscosity, as expected.…”

“…Rheological properties from dynamic shear rheometer (DSR) tests serve as an indicator of rutting and cracking performance of the binder, when used in an asphalt mix, whereas viscosity reflects the coatability of asphalt binder on aggregate at the hot mix asphalt (HMA) plant. A lower viscosity enables the effective coating of aggregate and permits lower processing temperature to reduce energy requirements and emission of volatile organics. , As shown in Figure , the viscosity measurements displayed considerable dependence on composition and a typical trend in viscosity with temperature. Addition of the RAP binder to the virgin binder increases the viscosity, as expected.…”

Rheology of Crumb Rubber-Modified Warm Mix Asphalt (WMA)

“…Unlike organic WMA additives, the chemical WMA impact on the physical and rheological properties of the asphalt binder is not significant [25][26][27]. Studies have shown that WMA additives might reduce the asphalt binder's high-temperature PG and rutting resistance [28,29]. One of the WMA additives that is currently being investigated is Zycotherm.…”