Reduces or eliminates water runoff.
Eliminates the newly mandated MSD stormwater runoff surcharge.
Allows for better use of land by reducing or eliminating detention basins.
Protects streams and replenishes aquifers.
For use with parking lots, streets, driveways, trails, etc.
Reduces the need for concrete curb and gutter, along with storm sewers.
LEED® credits available in three areas: Sustainable Sites, Materials & Resources, and Innovation and Design Process.
Energy Reduction & Recycling
Tear-off shingles are processed and introduced into our mixes.
Reclaimed Asphalt Pavement (RAP) can be incorporated into our mixes in excess of 20% for LEED® credit.
Reprocessed oil is used for heating aggregates for asphalt production.
Why Porous Asphalt?
Can earn credits under the LEED® System.
Has been shown to mitigate the urban heat island effect.
Provides storm-water management systems that promote infiltration.
Has a typical life span of more than 20 years.
Underlying stone bed tends to absorb and retain heat so ice and snow melt faster with the Porous mixture.
Typical pavement design for light duty and heavy duty performance. Asphalt Pavements and LEED® Certification
The first producer of Porous Asphalt in the St. Louis market, leading the way in supplying Porous Asphalt in several commercial projects to date.
Has internal testing facility for quality control.
Has received approval for Porous Asphalt as a Proprietary BMP Application by the Metropolitan Sewer District (MSD).
Uses recycled products, such as shingles, in porous mix.
Can provide Design/Build services for upcoming projects.
Will provide consultation for existing plans.
Recently provided Porous Asphalt for the City of St. Louis Board of Public Service on Cardinal Alley, a 130 foot alley which is the test site for the city’s first Porous application.
Leadership in Energy and Environmental Design (LEED®)
Developed by the U.S. Green Building Council, the Leadership in Energy and Environmental Design (LEED®) Green Building Rating System™ is the nationally accepted benchmark for the design, construction, and operation of high performance green buildings. LEED® promotes a whole-building approach to sustainability by recognizing performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality.
Earning LEED® Certification
To earn certification, a building project must meet certain prerequisites and performance benchmarks (“credits”) within each category. Projects are awarded Certified, Silver, Gold, or Platinum certification depending on the number of credits they achieve.
How Asphalt Pavements Contribute to Attaining LEED® Credits
Asphalt pavements contribute to LEED® credits in a variety of ways. Asphalt pavements are 100% recyclable. They are used and reused with each cycle of road paving. As such, credits associated with recycling and waste management are attainable. Pervious asphalt mixtures have been used in Ohio for over a generation. Research in the 1970s by the Franklin Institute launched Porous (pervious) Asphalt pavements, a strategy that both reduces quantity and improves quality of storm water runoff.
Tables have been developed to show for the different LEED® programs the potential credits attainable by using asphalt pavements. Each table provides the rating category, credit description, available points, and a discussion of the applicability/contribution that asphalt pavements have in attaining credits.
Porous Asphalt DESIGN CONSIDERATIONS
Designer of system should consider expected type and frequency of usage.
Test for permeability of soil early in design process. Soil and filtration rates of 0.1 inch – 10 inch per hour work best.
Porous surface permeability should be at least 8 inches per hour.
The bottom of the infiltration bed should be flat to maximize the infiltration area and reduce the amount of stone required.
Avoid compaction of soil base; if new fill is required, the addition of stone is recommended over adding compacted soil.
Not suitable for areas of recent fill (less than 5 years).
Use light equipment with tracks or oversized tires during grading to prevent compaction of the soil base
Install at least 4 feet above the seasonal high ground-water table to avoid contamination.
Design should include overflow drainage to remove excess stormwater.
Perforated pipe placed in the stone bed will distribute runoff evenly throughout the bed, and may provide additional storage volume, depending on the size of pipe.
Stone reservoir layer is placed in lifts and lightly rolled
Stone bedding layer should drain within 72 hours of a rain event.
Slope of pavement surface should be less than 5%
Aggregate for reservoir bed should be approximately 1 1/2 to 3 inches in diameter.
Reservoir layer is typically 12 to 36 inches deep (per engineering calculations).
Aggregate for reservoir must be clean-washed and contain at least 40% void space. Reference AASHTO Specification T19.
Place porous asphalt directly on stone bed in a single 3 inch lift then roll with 3 consecutive passes.
Use PG 76- 22 binder grade to prevent surface from being scuffed by vehicle wheels.
Roll asphalt when it has cooled enough to with stand a ten-ton roller.
Compact surface layer with one or two passes of roller; more frequent rolling can reduce infiltration capacity of pavement.
Control of sediment is critical – remove surface sediment with a vacuum or by sweeping; avoid power washing, as it will clog the system.
Prohibit use of sand or other de-icers that may clog system.
Design must provide for a backup method for water to enter stone reservoir (ex. stone-edged drain near wheel stop if curbing is not in place).
May not be suitable for “stormwater hot spots” (truck stops, gas stations, etc.) due to high level of contaminants present.
Use snow plows with caution during snow removal.
Not recommended in areas where wind erosion supplies significant amounts of windblown sediment.
Protect pavement from vehicular traffic for at least 24 – 48 hours after installation.
Post signs to prevent sanding or sealing of lot.
Potholes and cracks may be patched with traditional patching mix, unless more than 10% of porous surface area needs to be repaired.