There is a growing interest in the use of permeable pavements as a hardstand solution given the advantages this system can provide. The term permeable paving is often thrown around as a buzz word synonymous with sustainability, resource management, and environmental awareness. The aim of this 6 part guide is to provide specifiers, designers, installers, and end users the information required to make an educated decision on permeable pavements so they may benefit by adopting this technology.
For many years pavement designers have been educated in keeping water runoff above the surface and out of the pavement substructure, however permeable pavements are designed to do the EXACT opposite! A permeable pavement is any pavement designed for water to infiltrate the surface through a "permeable membrane".
Unlike traditional pavements where water runoff is directed through falls in the pavement's impermeable surface towards a drainage outlet, a permeable pavement allows the movement of water through the surface into the substructure of the pavement. From here the water can be stored, harvested, re-used or discharged at a controlled rate.
The permeable membrane can be a range of different materials. The most common include interlocking permeable paving units, no fines concrete, and porous asphalt however other materials do exist. Whilst allowing infiltration of water through it, the surface still needs to remain durable and intact for the duration of the pavements intended design life.
There are many benefits in using a permeable pavement. It can dramatically reduce site run-off by storing water within the substructure of the pavement. By doing this it will attenuate flood peaks by acting as an intermediary between an intense storm event and the existing storm water infrastructure. Storing and holding water within this substructure and allowing it to slowly penetrate into the subgrade can assist an area in recharging groundwater and maintaining the natural water cycle.
With the appropriate design considerations, permeable pavements can be utilized in a variety of hardstand applications ranging from light duty pedestrian walkways to heavy duty intermodal terminals. Typical parameters required to undertake a permeable pavement design include surface area, rainfall intensity, existing ground conditions, and pavement loading data - typically traffic but can include pallets, shipping containers, or specific industrial plant or equipment.
This Permeable Paving Guide will explore the common aspects of permeable pavements by covering the following topics:
Part 1: Introduction
Part 2: Components
Part 3: Material Specifications
Part 4: Applications
Part 5: Design
Part 6: Maintenance
Stay tuned for Part 2: Components to be published. This will contain a detailed breakup of a permeable pavement including surface, substructure, subgrade, geotextiles, edge restraints, and drainage.
If you require any additional information or want to discuss any points in further detail, please do not hesitate to contact me.