Porous asphalt pavements are a green infrastructure solution that provides the performance, ease of construction, and functionality of traditional asphalt pavements but with a permeable structure that helps manage stormwater.
Commonly used for parking lots and other light-duty applications, full-depth porous asphalt pavements are increasingly being used on roadways as part of efforts to mitigate flooding hazards, reduce hardscape, and improve sustainability. To help ensure these new porous asphalt roadways provide reliable performance under traffic, NAPA has published Structural Design Guidelines for Porous Asphalt Pavements.
“Often the design of porous asphalt pavements is focused on how well the pavement will handle water, not traffic,” said National Asphalt Pavement Association Vice President for Engineering, Research, & Technology Audrey Copeland, Ph.D., P.E. “For most parking lots and light-duty surfaces this may be a reasonable approach, but as public agencies look to use full-depth porous asphalt pavements on roadways a traditional structural design methodology is needed.”
Written by Charles W. Schwartz, Ph.D., and Kevin D. Hall, Ph.D., P.E., with the support of the NAPA–SAPA Pavement Economics Committee's Pavement Design Task Group, Structural Design Guidelines for Porous Asphalt Pavements discusses the structural design procedure for porous asphalt and the required inputs using the AASHTO 93 design method.
“This new publication helps pavement designers and agencies apply the widely used and accepted AASHTO methodology to porous asphalt pavements,” Copeland said.
The book includes guidance on determining structural design input values, calculating minimum layer thicknesses, and limits on effective structural thickness. Design examples are included for full-depth porous asphalt pavement systems with and without an asphalt-treated permeable base, as well as a catalogue of required layer thicknesses for different traffic levels.
Structural Design Guidelines for Porous Asphalt Pavements compliments the previously published Porous Asphalt Pavements for Stormwater Management: Design, Construction and Maintenance Guide. Both books are available as PDF downloads through the NAPA Online Store,.