In many cities, pavements (roads, platforms, pavement around buildings, parking areas,etc.) represent the largest percentage of a community’s land cover (30-40%),compared with roof and vegetated surfaces.
Cool pavements are reflective/permeable pavements that help lower surfacetemperatures and reduce the amount of heat absorbed into the pavement. Solar reflective "cool" pavements stay cooler in the sun than conventional pavements.Pavement reflectance can be enhanced by using reflective aggregate, reflective or clearbinder or reflective surface coating.
Permeable pavements—which allow air, water, and water vapour into the voids of apavement, keeping the material cool when moist.
Cool pavements may include:
- Conventional asphalt pavements, which consist of an asphalt binder mixed withaggregate, can be modified with high solar reflectance (SR) materials or treated afterinstallation to raise reflectance.
- Conventional concrete pavements (due to the grey colour they reflect sun light).
- Other reflective pavements, made from a variety of materials, are mostly used forlow-traffic areas, such as side-walks, trails, and parking lots. Examples include: Resin based pavements, which use clear tree resins in place of petroleum-based elements tobind an aggregate coloured asphalt and coloured concrete, with added pigments orseals to increase reflectance.
- Non-vegetated permeable pavements contain voids and are designed to allow waterto drain through the surface into the sub-layers and ground below. These materials canhave the same structural integrity as conventional pavements. Examples includeporous asphalt or open graded friction course asphalt pavements (they improve roadfriction in wet weather), and rubberized asphalt (also reduce noise), pervious concrete,brick or concrete pavement blocks.
- Vegetated permeable pavements use plastic, metal or concrete lattices to supportand allow grass or other vegetation grow in the lattices. They are suitable in areas withlow traffic flow.
IMPLANTATION: Soft/Medium/Hard
This NBS can be used at roads, platforms, pavement around buildings, parking areas etc. It can be easily replaced with any other pavement material when necessary.
AMORTISATION: Short term/Medium term/Long term/No amortization
The period of recovery of the initial economic investment of the NBS is between 0 and 5 years.