Experimental study on a novel polymer Warm Mix Asphalt additive for low energy road pavements

The demand for transportation infrastructure grows, impacting the environment with traditional hot asphalt mixes. Warm mix asphalt (WMA) emerges as a solution, lowering production temperatures to reduce fuel use and emissions. However, WMAs face challenges like moisture susceptibility and incomplete drying affecting long-term performance. This study introduces a polymer modification enhancing WMA's performance. The research involves the preparation of bituminous binders and mixtures, incorporating a commercial polymer warm mix additive. The modified bituminous mixture, representing Polymer-Modified Warm Mix Asphalt (PMWMA) while the neat bituminous mixture is representing Hot Mix Asphalt (HMA). Rheological characterization of bituminous binders and analysis of the physical, geometrical, and mechanical properties of asphalt mixtures were conducted as part of the study.The analysis of rheological properties of bituminous binders revealed that, although the polymer- modified bituminous binder exhibited significantly higher viscosity compared to the neat binder, the MSCR data indicated a lower elastic response. Physical tests on asphalt mixtures reveal lower air voids in the modified version, potentially improving resistance to moisture damage and rutting. Results of ITS and ITSM tests indicate that PMWMA outperforms traditional HMA in terms of tensile strength and stiffness, suggesting better durability. The higher ITSR value for the modified mixture is a significant positive outcome, indicating enhanced moisture resistance and potentially greater durability. Despite the overall good mechanical features of the asphalt mixture, at the binder level the polymer modification tends to be hindered by the chemical additive of warm technology. The study confirms that PMWMA is a viable alternative to HMA, providing satisfactory performance characteristics while also offering environmental advantages.