Next Generation Permeable Pavement for Enhanced Durability and Functionality

Porous Asphalt Concrete (PAC), also known as Open-Graded Friction Course (OGFC), is known for its high permeability, which provides benefits such as enhanced rainwater drainage, improved skid resistance, and reduced hydroplaning risks. These characteristics are due to its high air void content, allowing water to flow through the pavement and reducing splash, spray, and noise compared to conventional asphalt mixes. However, this high air void content also contributes to durability concerns, such as raveling, stripping, and clogging, which can reduce service life and increase costs, making OGFC more expensive than conventional asphalt mixtures. This research focuses on identifying the failure mechanisms of OGFC and explores innovative methods to improve its durability and cost-effectiveness. Six OGFC mixes were tested, including a control mix with PG 76-22 binder. Three of the modified mixes used steel slag, recycled waste plastic, and reclaimed asphalt pavement (RAP) as partial replacements for the aggregate in the control mix. Additionally, one mix replaced the PG 76-22 binder with highly modified asphalt (HiMA) and another included hydrated lime slurry as a modification. These mixes were evaluated for key performance indicators including permeability, resistance to cracking, moisture damage, rutting, and raveling. Binder bonding strength tests were also conducted to assess adhesive strength of the different modifications. Findings suggest that replacing aggregate with steel slag, reclaimed asphalt pavement and recycled waste plastic, using HiMA binder, and modifying the OGFC with hydrated lime slurry improved durability and performance. A cost-effectiveness analysis indicated the economic viability of these modifications. Future research is recommended to examine the environmental impacts of using recycled materials and to optimize the rates of modification for specific mix and operating conditions.