Abstract Manager

Bitumen stabilized materials (BSM) are widely used for flexible pavement rehabilitation due to their ability to incorporate up to 100% reclaimed asphalt pavement (RAP) without the need for heat, making them an environmentally friendly alternative. The use of bitumen emulsion in these mixtures further enhances sustainability by reducing energy consumption and emissions. However, the mix design process for BSM varies depending on factors such as the amount of RAP, the type of binder (bitumen emulsion or foamed bitumen), the presence of cement, and regional design methodologies.

This study first presents a literature review of the different mix design methodologies used globally for BSM. It then focuses on optimizing the volumetric properties of BSM mixtures, emphasizing their impact on mechanical performance and durability. Volumetric optimization is essential to ensure proper workability, compactability, and long-term stability of these mixtures.

The research examines the use of the Bailey method to guide gradation design and improve volumetric characteristics. Laboratory testing demonstrated that an 80% LUW gradation, with a controlled voids-filled liquid (VFL) content of 85%, produced the best volumetric properties among the tested mixtures. This optimization resulted in improved compaction and mechanical stability, leading to enhanced durability and resistance to pavement distress.

This study underscores the importance of integrating advanced gradation design methods with volumetric analysis to optimize BSM mixtures using 100% RAP. The findings provide valuable insights for pavement engineers, offering a sustainable, cost-effective, and high-performance approach for road construction and rehabilitation through cold recycling technologies.