BMP Monitoring Sites - Urban Drainage and Flood Control District

UDFCD BMP MONITORING SITES
Porous Asphalt Pavement
Installation Guidelines
Design Thickness
Asphalt Binder
Design the thickness of the porous
asphalt slab to have a finished
thickness of 2.5 inches with a
bituminous binder of 5.5% to 6.5% by
weight dry aggregate.
Use neat asphalt binder modified with an elastomeric
polymer to produce a binder meeting the requirements of
PG 76022. The elastomeric polymer shall be styrenebutadiene-styrene
(SBS) or approved equivalent, applied
at a rate of 3% by total weight of the binder. The
composite materials shall be thoroughly blended at the
asphalt refinery or terminal prior to being loaded into the
transport vehicle. The polymer-modified asphalt binder
shall be heat and storage stable.
Aggregate Gradation Aggregate in the asphalt mix shall be a minimum 90%
crushed material and have the following gradation:
U.S. Standard Sieve Size Percent Passing
0.5-inch (12.5 mm) 100
0.375-inch (9.5 mm) 75-95
#4 (4.75 mm) 25-35
#8 (2.36 mm) 10-15
#16 (1.18 mm) 5-10
#30 (600 µm) 1-5
#200 (75 µm) 1-3
Batch Testing
To test draindown, air voids and abrasion, prepare
three batches containing asphalt binder contents of
5.5, 6.0 and 6.5 percent by dry weight aggregate. The
asphalt content that provides the best results according
to the following table shall be selected as the final mix.
Test the final mix for Moisture Susceptibility and
Resistance to Stripping. If the final mix does not meet the
requirements for moisture susceptibility and resistance to
stripping, add hydrated lime until the requirements are
met.