ABSTRACT
Keywords: Warm Mix Asphalt, moisture susceptibility, rutting, ESR, pavement performance
1 INTRODUCTION
Warm Mix Asphalt (WMA) refers to the use of technology and additives to lower the mixing and compaction temperatures during the production of asphalt concrete [1]. Potential benefits of WMA use include energy-cost savings, extended paving season, increased hauling distances and improved compaction in the field [2, 3]. Various technologies currently used to produce warm asphalt mixes are broadly classified into categories based on how they modify the production of the mix [4]. Several other warm mix production methods have been studied to date [4, 5], a few of which are listed below according to type of modification:
• Asphalt foaming technology-Astec Double Barrel Green, Foamer, WAM-Foam • Asphalt Foaming by Zeolite-Natural zeolites, Synthetic zeolites-Aspha-Min (Aspha-
Min GmbH, Germany), Advera (PQ Corporation, USA) • Bitumen Viscosity Modifiers-Sasobit (Sasol Wax GmbH, Germany), Licomont BS 100
(Clariant, Switzerland) • Chemical Additives-Evotherm (MeadWestvaco, USA)
Use of WMA in asphalt pavement construction has raised two primary performance issues-moisture damage and low stiffness leading to rutting [5, 6]. Other factors that affect warm mix asphalt use are issues with workability and compactability [4, 6], determination of mixing and compaction temperatures for different binder types, aggregate compatibility with WMA modifier, extent of modification (modifier quantity or water percentage for foamed asphalt), use of anti-stripping additives amongst others [5-13]. The research study presented in this paper sought to evaluate the performance of warm asphalt mixtures prepared using
three types of WMA technology-Sasobit (viscosity modifier), Advera (zeolite) and the Foamer device (asphalt foaming technology).
