Pervious concrete is a mixture of coarse aggregate, Portland cement, 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.
Carefully controlled amounts of water and cementitious materials are used to create a paste that forms a thick coating around aggregate particles without flowing off during mixing and placing. Using just enough paste to coat the particles maintains a system of interconnected voids.
The result is a very high permeability concrete that drains quickly. Due to the high void content, pervious concrete is also lightweight, 1600 to 1900 kg/m3 (100 to 120 lb/ft3).
After placement, pervious concrete resembles popcorn. Its low paste content and low fine aggregate content make the mixture harsh, with a very low slump. The compressive strength of pervious concrete is limited since the void content is so high. However, compressive strengths of 3.5 to 27.5 MPa (500 psi to 4000 psi) are typical and sufficient for many applications.
NRMCA’s Pervious Concrete Contractor Certification
This program is designed to be administered locally by local sponsoring groups in conjunction with planned training sessions or demonstrations of pervious concrete placement. NRMCA provides certification exams and performance evaluations to approved local sponsoring groups for administering the certification. Click here for the current list of local sponsoring groups.
Articles/Research
Increasing Exfiltration From Pervious Concrete and Temperature Monitoring
Journal of Environmental Management Article
J.S. Tyner*, W.C. Wright, P.A. Dobbs;
Department of Biosystems Engineering and Soil Science, Univ.of TN, Knoxville
Pervious Concrete Research Compilation: Past, Present and Future
Updated August 2012
Compiled by: Dr. Heather J. Brown; Concrete Industry Management Program; Middle Tennessee State University
Porous Concrete Sidewalk Cleaning Trial Using a Leaf/Litter Vacuum Machine
Craig Tosomeen, City of Olympia, WA; September 2006
Area-Rated Rational Coefficients for Portland Cement Pervious Concrete Pavement
ASCE Journal of Hydrologic Engineering; Volume 11, Issue 3 (May 2006)
When It Rains, It’s Porous
Courier-Journal, Louisville, KY
For additional pervious concrete pavement resources, visit NRMCA’s website
