In March 2011, the Georgia Concrete and Products Association sponsored a pervious concrete laydown demonstration at the site of the Georgia Association of Water Professionals headquarters in Marietta, Ga. The 6-inch-thick pervious pavement replaced over 1,150 square feet of deteriorated asphalt parking spaces, using two types of synthetic fiber reinforcement to add durability to the light and medium-to-heavy duty pavement areas.
Performed with industry-donated materials and volunteer labor, the project was intended to demonstrate the placement and finishing practice of pervious concrete, as well as expose the user-friendly nature of fiber reinforcement. The light-duty parking space areas were reinforced with 1.5 pounds per cubic yard of 1.5-inch-long Forta Green-Net fiber, a net-shaped fiber made from 100 percent recycled polypropylene materials. For the medium-to-heavy duty parking and driving areas, 7.5 pounds per cubic yard of 1.5-inch-long Forta-Ferro macrosynthetic fiber was added to the pervious concrete for additional toughness. In both cases, the fibers mixed and distributed well, and offered minimal visible evidence on the pavement surface.
Of special interest, previous laboratory work-ups of the project mix using 7.5 pounds of the Forta-Ferro had revealed an increase in concrete yield of approximately 7 percent , allowing for significant material savings in cement and aggregate. This successful demonstration project has led to additional project applications.
Application: pervious concrete parking lot
Owner: Georgia Association of Water Professionals, 1655 Enterprise Way Marietta, Ga., 30067
Contractor: Volunteer labor directed by Dale Fisher, director of the National Pervious Concrete Pavement Association
Ready-mix supplier: Thomas Concrete of Woodstock, Ga.
Fiber type/length: Green-Net 1.5-inch. length at 1.5 pounds per yard; Forta-Ferro 1.5-inch. length at 7.5 pounds per yard
Cubic yards: 21 total cubic yards
Finishing method: Roller-screed strike-off, covered with plastic and rolled; plastic cover cure
Slab thickness/dimensions: 6-inches thick, approximately 1,150 square feet