BMP Monitoring Sites - Urban Drainage and Flood Control District

UDFCD BMP MONITORING SITES
Pervious Concrete Pavement
Typical Details
Use utility vault w/
lid to collect
underdrains.
Monolithically poured porous
concrete.
1in
5"**
D = 0.67'(8") min.**
1" (min.) C-33 Sand
6" (min.)
Underdrain
trench
6" (min.) trench depth
16 MIL (mon.) plastic impermeable membrane
on top of subgrade when required and at bottom
of underdrain trench.
Woven geotextile fabric meeting:
ASTM D4751-AOS US Std. Sieve #50 to #70,
ASTM D4633 min. trapezoidal tear strength 100 x 60 lbs,
Minimum COE specified open area of 4%.
Section A-A
** For personal vehicles & pickup trucks.
Thicker section may be required for
heavier vehicles.
Consult with pavement engineer for
needed thickness of concrete slab.
*** Base course: AASHTO #67, #8 or #4 aggregate
with all fractured faces.
So = 0% to 2% (max.)
Lmax = D/(1.5*So)
A
Monolithically poured porous concrete
(mix of AASHTO #8 or #67 gravel
and portland cement per specifications
in the BMP Details and Specifications
Chapter of this Manual). No phosphorous
based admixtures allowed in the PCP mix.
5"**
D = 0.67'(8") min.**
So = 1% (min.)
Install 16 MIL (min.)
impermeable membrane
under pipe & wrap it on d/s
side to within 1in(+ 2"/-0") 1 of
top of gravel to serve as
horizontal flow barrier.
A
When certified tests show percolation rates of less than
60 minutes per inch of drawdawn under the PP bottom
and infiltration is allowed, eliminate the bottom sand
layer and underdrains.
When Type C soils are present and when infiltration is
allowed, unless percolations show otherwise, eliminate
the bottom sand layer, use underdrains and geotextile
liner instead of an impermeable one under the gravel.
When the underlying soils are NRCS Type D or
expansive, when existing or proposed building is within
10 feet, and/or when land uses pose risk to groundwater
contamination, use 16 mil minimum thickness
impermeable liner under and on sides of the pavement
sand and gravel media.
Pervious Concrete Pavement Section