Abstract
Abstract Cold Paving Hot Mix Asbuton (CPHMA) is a popular choice for building flexible pavement because it is better for the environment, especially in places where heating is not readily available. But its mechanical performance is often worse than that of regular hot-mix asphalt, so it needs to be improved by changing the materials. This study examines the relative impacts of two mineral-based additives–fly ash-derived geopolymer powder and Portland cement–on the Marshall performance of CPHMA in tropical conditions (30 °C) The asphalt content remained constant at 6.9%, whereas both additives were integrated in varying proportions of 0.5%, 1.0%, and 1.5% by total mixture weight. The Marshall method, as outlined in SNI 06-2489-1991, was used to test all of the mixtures for stability, flow, and Marshall Quotient (MQ). The findings indicate that the integration of both materials substantially affected the stiffness and internal cohesion of CPHMA. The specimens that had cement added to them were stronger, with a maximum stability of 392.72 kg and a MQ of 133.91 kg/mm at 1.5% cement content. The geopolymer-modified mixtures, on the other hand, were more uniform and had a moderate improvement, with a stability of 271.76 kg and a MQ of 74.79 kg/mm at 1.5% addition. All samples were still below the 500 kg minimum stability specification, but both additives made the mixture more resistant to deformation and better at bonding. The comparative analysis shows that adding geopolymer powder and Portland cement to CPHMA improves its mechanical performance overall. These results show that geopolymer and cement-based modifiers could be used as eco-friendly and energy-efficient materials for cold-mix asphalt in tropical climates.