Development of a framework for the structural design of long-lasting porous asphalt pavement for high-traffic volume roadways

Historically, porous asphalt pavements were considered one of the best practices for stormwater management. The primary application of these structures is mainly on low-volume roads, parking lots, shoulders, walkways, etc. Consequently, hydrological aspects dominated their design, with structural design receiving less attention. However, structural design is essential when constructing porous asphalt pavements on heavily trafficked roads. This study develops a framework that uses AASHTO 93 and Pavement ME to design long-lasting porous asphalt pavements on high-traffic roadways. A case study of a roadway in New Jersey with a traffic volume of over 10 million ESALs validates the developed framework. Experiments were conducted on laboratory-mixed and laboratory-compacted porous asphalt mixtures, including confined dynamic modulus, to collect design inputs. There is a significant increase in confined dynamic modulus compared to unconfined dynamic modulus for open-graded porous asphalt mixtures. The study demonstrated the limitations of the current Pavement ME software for analyzing porous asphalt pavement layers. The AASHTO 93 method is more appropriate for long-lasting porous asphalt pavement structural design. Hence, the AASHTO 93 design with a porous asphalt layer thickness of 6 in. is analyzed in Pavement ME for performance prediction. Even though the sections failed in all other distress, as predicted by Pavement ME, they did pass the rut resistance criteria. The total rut depth of the three pavement sections satisfied the requirements (<1 in. in the case study) for 50 years to carry 13 million ESALs of traffic loading.