Evaluating the performance of porous asphalt mixtures with polymer-modified and unmodified bitumen

Abstract Porous Asphalt (PA), with its open-graded structure and high air voids, offers excellent water permeability, reducing runoff, noise, and heat from the pavement. However, it has low strength and durability and is prone to clogging, as its large pores can be filled with particles from various sources. This study aims to evaluate the performance of PA mixtures incorporating polymer-modified bitumen (PMB) to enhance these properties, compared to mixtures with unmodified bitumen. For this purpose, PA mixtures with styrene–butadiene–styrene (SBS) as the PMB and unmodified bitumen Pen grade 60/70, with varying porosities (12%, 16%, 20%), were evaluated. A range of critical performance parameters, including stability, flow, durability, permeability, clogging resistance, and skid resistance, were assessed to determine the overall effectiveness of each mixture. The results show that PA mixtures with PMB exhibit better Marshall Stability, flow, and resistance to aggregate loss, as seen in the lower mass loss in the Cantabro test. These improvements are due to PMB’s enhanced adhesion and elasticity. Additionally, PA mixtures with PMB have significantly higher permeability compared to those with unmodified bitumen, likely because PMB helps maintain air voids during compaction. These mixtures also show better clogging resistance, with higher remaining permeability after 10 cycles, and improved skid resistance due to better aggregate retention and surface texture. Overall, PA mixtures with PMB outperform those with Pen 60/70 in key performance areas, enhancing both mechanical and functional properties, and offering more sustainable solutions.