Performance evaluation of Aspha-min modified warm mix asphalt

Abstract

The conventional use of Hot Mix Asphalt (HMA) in flexible pavement construction presents environmental challenges due to high energy demands and emissions. To address these concerns, Warm Mix Asphalt (WMA), with reduced mixing and compaction temperatures, offers a more sustainable alternative by lowering fuel consumption and air pollution. Aspha-min, a zeolite-based additive, employs foaming technology to facilitate asphalt workability at lower temperatures. This study evaluates the performance of Aspha-min modified WMA under Sri Lankan conditions. Three Aspha-min dosages: 0.25%, 0.30%, and 0.35%, were assessed at mixing temperatures of 125 °C, 130 °C, and 135 °C. Key performance indicators, including Marshall stability, bulk specific gravity (Gmb), air void content, and Tensile Strength Ratio (TSR), were evaluated in accordance with ASTM standards. Furthermore, the results were analyzed to ensure compliance with the Standard Specification for Construction and Maintenance (SSCM) requirements for wearing courses. The findings revealed that the mix containing 0.30% Aspha-min at 130 °C demonstrated the most favorable performance, achieving high stability, high moisture resistance, and acceptable air void content while maintaining compaction characteristics similar to conventional HMA. This indicates that Aspha-min modified WMA can effectively reduce production temperatures while maintaining structural performance. The findings support its application as a sustainable alternative in pavement construction in Sri Lanka.