Applications: All applications as alternative to conventional concrete, including parking lots, low speed/volume streets, pathways, and other pedestrian applications.
Service Life: 15-30 years
Pervious concrete is concrete mixed with less sand and fine particles than conventional asphalt. The concrete is then laid above a crushed stone aggregate base to allow for water infiltration. Water is able to permeate the concrete due to void spaces of 18-20%, which also reduces the weight of pervious concrete by 20-30% compared to conventional concrete. Rigid pavements like concrete typically do not require aggregate bases for structural stability, though deep aggregate bases are recommended for cold climates like the northeast. Suppliers are easy to find, as pervious concrete is mixed and applied using the same equipment and methods as impervious concrete. The lack of fine particles gives pervious concrete a coarser look than conventional concrete.
As with other pervious pavements, proper maintenance (primarily vacuum sweeping) is necessary to maintain high rates of infiltration. Infiltration rates are also highly dependent on the subgrade soil. Sandy soils have highest infiltration capacity and increased load bearing capacity, but lower treatment capacity. Potholes and cracks can be fixed with patching mixes unless >10% of the surface needs replacement. The maximum slope of pervious concrete exceeds porous asphalt and allows for a slope of up to 12% while maintaining infiltration.
- Enhances groundwater infiltration while reducing stormwater runoff volume, rate, and pollutants.
- Contributes to lower urban air temperatures when moist due to higher reflectivity and evaporative cooling.
- Reduces occurrence of black ice/freezing puddles in cold climates; requires fewer applied deicers.
- Allows pollutants to infiltrate groundwater. Should not be installed in areas where hazardous material spills are possible.
- Plowed snow piles and improper deicing treatment can clog void spaces and reduce infiltration rate (sand should not be used). Snow plow blades can damage surface.
- Coarse appearance can be aesthetically displeasing (relative to conventional concrete).
Regulatory Impacts and Requirements
Financing Options, Incentives, And Rebates
- Municipal stormwater abatement service fees – Municipal-level
- Coastal Pollutant Remediation (CPR) Grant Program – MA State
- Clean Water State Revolving Fund (SRF) – MA State
- Section 319 Nonpoint Source Competitive Grant – Funding provided under federal Clean Water Act
- 604b Water Quality Management Planning Grant – Funding provided under federal Clean Water Act
- Drinking Water Supply Protection Grant Program – MA State
- Investments for Public Works and Economic Development Facilities grants
- Community Development Block Grants
- Surface Transportation Program – Funding provided by Federal Highway Administration
- Transportation Infrastructure Finance and Innovation Act (TIFIA) Program
- MassWorks Infrastructure Program – MA State
- Chapter 90 – MA State
SAMPLE OF SUPPLIERS
Photo credit: User PerviousConcrete on Wikimedia Commons