PERVIOUS CONCRETE

Benefits include:

  • Reduces the amount of untreated runoff discharged into storm sewers
  • Eliminates hydrocarbon pollution from asphalt pavements and sealers
  • Mitigates pollutants harming the eco-system
  • Channels more water to tree roots and landscaping
  • Allows for more efficient land development
  • Ability to reuse storm water for irrigation
  • LEED

It is made up of Portland cement, coarse aggregate, water and little to no sand. A typical pervious concrete pavement has a 15-25% void structure and allows 3-8 gallons of water per minute to pass through each square foot. The key for a successful pervious placement falls in the design of the pavement system, the right mix design and a knowledgeable installer.

The water and cement are combined together to make a dry paste which coats all the aggregate particles. As this paste hardens the aggregates are locked together and the voids between them allow water to pass through. Having the right mix design is critical so that the paste is not too wet, which can cause a clogged pervious pavement, or too dry which can jeopardize the strength. Pervious has a very low water/cement ratio and a very low slump. In fact, slump is not a valid test for pervious. Because of the high void content of pervious concrete strengths max out at around 4,000 psi compressive, which is sufficient in many applications.

Click on the link below to learn more about Envirocrete:
Envirocrete

http://www.perviouspavement.org/index.html