PERVIOUS CONCRETE - PERFORMANCE

While  pervious  concrete  can  attain  a  compressive  strength  ranging  from  400  to  4,000 psi (2.8–28 MPa), it is not specified or accepted on the basis of strength since  to date there are no standardized testing methods available. In the case of pervious concrete, the more important component that needs careful attention is the void con- tent.  The  structure  of  pervious  concrete  is  such  that  it  consists  of  interconnected  voids,  which  help  drain  water  very  quickly.  Typically,  hardened  pervious  concrete  will have a void content of 15%–25%, with a water  ow rate exceeding 100 in./h, as  measured by ASTM C1701.

The durability of pervious concrete in a freeze–thaw environment is a subject of  extensive  debate.  There  have  been  questions  raised  about  the  materials’  durability  under  these  conditions.  The solution  to  the  problem  lies  in  ensuring  that  pervious  concrete  in  freeze–thaw  conditions  does  not  become  fully  saturated.  This  can  be  ensured  by  installing  the  pervious  concrete  pavement  on  a  thick  layer  (between  6  and  18  in.)  with  open  graded  stone  base.  Practical  application  in  several  countries  has proven beyond doubt the high durability of this environmentally friendly structural material. Pathways built with pervious concrete have lasted for well over four  decades in some instances. The key to longevity of structures made up of the material is also dependent on proper compaction and curing.