The Federal Highway Administration (FHWA) has released a new Tech Brief titled “Permeable Interlocking Concrete Pavement” that presents an overview of permeable interlocking concrete pavement (PICP) and its use. General information is provided on PICP compositionwith a summary of benefits, limitations, and characteristics. Important considerations, such as hydrologic design, structural design, construction, and maintenance, are also provided. This Tech Brief supersedes FHWA Publication No.FHWA-HIF-15-007, JANUARY 2015.
PICP consists of solid concrete paving units with joints that create openings in the pavement surface when assembled into a pattern. The joints are filled with permeable aggregates that allow water to freely enter the surface. The permeable surface allows flow rates as high as 1,000 in./hr (2,540 cm/hr) (Borst 2010).
The paving units are placed on a bedding layer of permeable aggregates that rests over a base and subbase of open-graded aggregates. The concrete pavers, bedding and base layers are typically restrained by a concrete curb in vehicular applications. The base and subbase store water and allow it to in filtrate
into the soil subgrade. Perforated underdrains in the base or subbase are used to remove water that does not in filtrate within a given design period, typically 48 to 72 hours. Geosynthetics such as geotextiles, geogrids, or geomembranes are applied to the subgrade depending on structural and hydrologic design objectives. Separation geotextiles are used on the sides of the base/subbase to prevent entrance of fines from adjacent soils.
This Tech Brief presents and details PICP’s:
BENEFITS
• Construction
• Reduced Runoff and Improved Water Quality
• Site Utilization
• Drainage System
• Reduced Operating Costs
• Paver Surface/Units
• Ease of Maintenance and Repairs
APPLICATIONS AND LIMITATIONS
TYPICAL PROPERTIES AND CHARACTERISTICS
• Concrete Paving Units and Jointing Materials
• Open-Graded Bedding Course
• Site Characteristics
• Structural Design
• Open-Graded Base Reservoir
• Open-Graded Subbase Reservoir
• Geosynthetics
• Design
CONSTRUCTION CONSIDERATIONS
• Construction Checklist – Pre-Construction Meeting
• Excavation
• Foundation Walls
• Water Supply
• Soil Subgrade
• Geosynthetics
• Subbase, Base, Bedding, and Jointing Aggregates
• Edge Restraints
• Permeable Interlocking Concrete Pavers
• Final Inspection
MAINTENANCE
Routine
Remedial
Winter
PERFORMANCE
SUMMARY AND FUTURE NEEDS
REFERENCES
For the Tech Brief titled “Permeable Interlocking Concrete Pavement”, please click on image above, or go to: https://www.fhwa.dot.gov/pavement/concrete/pubs/hif19021.pdf