04/29/2026
Permeable Interlocking Concrete Pavement System
This technical illustration demonstrates the layered composition of a Permeable Interlocking Concrete Pavement (PICP) system. Unlike traditional solid surfaces, this engineering approach is designed to manage stormwater at the source by allowing water to infiltrate through the surface joints and into a specialized stone reservoir. This process filters pollutants and reduces runoff, making it a sustainable choice for modern urban infrastructure and eco-friendly landscaping.
Key Components & Features
Concrete Pavers & Permeable Joints: The surface layer consists of durable concrete units separated by small gaps filled with high-permeability aggregate, allowing water to pass through immediately.
Concrete Curb: Provides structural edge restraint to prevent the pavers from shifting under load.
Open-graded Bedding Course: A thin layer of small, washed stone that provides a level setting bed for the pavers.
Open-graded Base & Subbase Reservoirs: These thick layers of larger crushed stone act as a structural foundation and a storage chamber, holding water until it can infiltrate the soil or be diverted.
Geosynthetic Layers: Specialized geotextile fabrics line the excavated soil walls and base to prevent soil migration and maintain the structural integrity of the stone reservoir.
Underdrain System: A perforated pipe located at the bottom of the reservoir to carry away excess water when the soil reaches its maximum infiltration capacity.
Soil Subgrade: The natural earth foundation that serves as the final destination for filtered water returning to the groundwater table.
Design Summary
The system represents a shift from "gray" infrastructure to "green" engineering by mimicking the natural hydrologic cycle. By utilizing a multi-layered filtration and storage strategy, this design provides a load-bearing surface suitable for vehicular or pedestrian traffic while simultaneously acting as a high-performance drainage solution. It is an essential component of Low Impact Development (LID) and Sustainable Drainage Systems (SuDS).