What is pervious pavement?
Driveway or parking surface that looks like any other impervious pavement, except that the visible stone at the surface is much larger and more course. The larger stone provides void space that allows water to run through it into an underground stone pit. The stone pit can either serve as an infiltration pit or detention area to slowly release the runoff at a more controlled rate.
Pervious portland cement concrete is typically made with narrowly graded coarse aggregate, little or no fine aggregate, and a very low water/cementitious materials (w/cm) ratio. The result is a stiff, pebbly mixture with 15 to 25 percent of its volume being interconnecting pores through which water can flow. As an emerging alternative, several recently introduced systems use fine aggregates with proprietary admixtures to assure porosity. Installing pervious pavement differs in a number of respects from conventional concrete pavement. The concrete is typically placed on a base course of clean, gap graded gravel or crushed rock that acts as a reservoir to hold water until it can infiltrate into the soil. The concrete is placed in conventional forms except that a screed strip 1⁄2 inch to 3⁄4 inch high is placed on top of the forms. After the concrete is placed, the screed strips are removed and a vibratory screed is used to compact the concrete to the required density and thickness, usual
Pervious pavement, or porous pavement, is a permeable pavement surface that allows rain water to soak through the surface. Below ground, water is temporarily stored until it can infiltrate into the soil. This reduces the volume of stormwater runoff and helps filter pollutants. Pervious Asphalt Pervious asphalt looks a lot like traditional asphalt but has large pores in the surface. Below the surface, a rock chamber two to three feet deep stores water until it can infiltrate into the soil. Pervious Pavers Pervious pavers look much like other types of pavers, but the corners where pavers meet are filled with gravel. Water can soak into the gravel area and seep into the soil below.
Pervious Pavement is a unique cement-based concrete product that has a porous structure that allows rainwater to pass directly through the pavement and into the soil naturally. This is achieved without compromising the strength, durability, or integrity of the concrete structure itself. The pavement is comprised of a special blend of Portland Cement, coarse aggregate rock, and water. Once dried, the pavement has a porous texture that allows water to drain through it at the rate of 8 to 12 gallons per minute, per square foot. That’s impressive considering tests conclude that a square foot of bahia sod drains at the rate of 2 1/2 to 3 gallons per minute. This remarkable flow through ratio inspired us in coining the phrase “…The pavement that drinks water.” A Proven Track Record… This type of pavement has been in use throughout Europe for about 50 years. In 1970, here in the United States, Jack Paine a civil engineer and several other members of the Florida Concrete & Products Associa
