Permeable pavements
Contents |
[edit] Introduction
A pavement with base and sub-base that allows the water to infiltrate or pass through the surface is known as Permeable Pavement. It not only helps to reduce the surface run off but also effectively traps the pollutants and solid particles in the water avoiding ground water pollution.
Evaporation of water at or below the surface also produces surface cooling, as opposed to the traditional heating of paved areas. This is especially beneficial in cities which experience extremely high temperatures in summer – traditional “blacktop” temperatures can make some public spaces unusable in warmer weather.
Generally, permeable pavement structures consists of a pervious / permeable surface course which may be of Asphalt concrete or Portland cement concrete laid over a layer of fine aggregates, which acts as a filter layer for infiltrating storm or rain water. Underneath this filter layer is a uniformly-graded gravel course to store water, which ultimately penetrates into the ground. General design practice requires an un-compacted natural ground, which allows relatively easier discharge of water avoids any standing water under the pavement structure that may cause structural failure.
Permeable pavements are generally recommended for residential, commercial and urban areas but not highways, motorways and streets with heavy traffic loading as these pavements are not designed with structural capacities to support such loads.
[edit] Advantages
Permeable pavements offer many benefits, both aesthetic and practical. Some of the benefits are listed below:
- Reduces storm water runoff, total water volume, and flow rate.
- Treats water runoff.
- Increases groundwater infiltration and recharge.
- Provides local flood control.
- Improves the quality of local surface waterways.
- Reduces soil erosion.
- Reduces the need for traditional storm water infrastructure, which may reduce overall project costs.
- Increases traction when wet.
- Reduces splash-up in trafficked areas.
- Extends the life of paved areas in cold climates as there is less cracking and buckling from the freeze-thaw cycle.
- Reduces the need for salt and sand use during the winter, as there is little or no black ice.
- Requires less snow-plowing.
- Reduces groundwater pollution.
- Offers evaporative cooling.
[edit] Disadvantages
Some of the disadvantages associated with these pavements are:
- Highly contaminated runoff can be generated by some land uses where pollutant concentrations exceed those typically found in storm water.
- Heavy traffic loads can lead to pavement failure.
- In cold climates, salts used for the removal of snow, contains chlorides that could migrate through the porous pavement into groundwater.
- Frequent maintenance is required to prevent the blockage of pores.
- Additional maintenance cost compared to conventional pavement.
[edit] Related articles on Designing Buildings Wiki:
IHBC NewsBlog
APPG on ‘Conservation, Places and People’ Opens first Parliamentary Inquiry
The Inquiry is into ‘21st Century Places – Values & Benefits‘
Historic Photographer of the Year 2020 Winners Announced
The awards showcase the very best historic places and cultural sites from across the globe.
IHBC Launches new ‘Guidance Note’ on Alterations to Listed Buildings
The IHBC’s latest Toolbox Guidance Note, on ‘Alterations to Listed Buildings’ has been issued following UK-wide consultation.
Caithness Iron Age Stone Tower Conserved
The ruins of Ousdale Burn Broch, north of Helmsdale in Caithness, had fallen into further disrepair over the past 130 years.
The American Air Museum at Duxford has been listed Grade II*
Europe’s largest air museum and Britain’s best-preserved Second World War airfield – has been included in Grade II* listing, even though technically too recent.
West Dean College wins Sussex Heritage Trust Award 2020 for Roof Restoration
The College of Arts and Conservation has won the award for a for a project which provides or improves facilities for the community, including a £5.8M restoration of the College’s 126-year-old roof.
Stowe North Hall & WMF: A Step Closer to Completion
Completion of the restoration of Stowe House’s North Hall, largely funded by World Monuments Fund (WMF), came a step closer this summer with the installation of a statue of Mercury opposite the imposing Laocoön group installed last year.
IHBC CREATIVE Conservation Fund launched
The CREATIVE Conservation Fund helps the IHBC generate and distribute funds exclusively to deserving causes in built and historic environment conservation.
The tunnel near Plymouth with a nuclear secret
For years, there have been rumours whispered around Plymouth and Cornwall about so-called ‘nuclear tunnels’ that exist beneath the Tamar Valley.
141 bridges with ‘very poor’ rating remain open to avoid disruption
Just under half of England’s busiest bridges are severely defected or damaged, but have remained open due to concerns about an influx of traffic should repairs be ordered, it has been revealed.