1.1. Permeable pavement
Presently natural resources are increasingly consumed due to
rapid urbanization and thereafter human construction activities,
so that various strategies are being investigated by engineers to
protect and restore natural ecosystems in the world. Permeable
(porous/pervious) pavement is termed as comprising materials
that facilitate stormwater infiltrate and transfer to the underlying
subsoil [1]. With sub-structure which stores water underground
temporarily, it is called permeable pavement system. Instead of
installing rainfall detention ponds or soakaways, this new system
is more cost effective compared to the traditional impervious pavement.
Meanwhile, it has been acknowledged by many researchers
that permeable pavement system is capable of reducing the
sediments and contaminants for lessening the pollutant loads on
stormwater, thus it is considered as an economic and environmental-
friendly construction as a part of city drainage system.
Ferguson identifies nine categories of permeable pavement [2]:
porous aggregate, porous turf, plastic geocells, open-jointed paving
blocks, open-celled paving grids, porous concrete, porous asphalt,
soft paving materials, and decks. Because of their many environmental
benefits there has been an increase in the use of permeable
pavements over the past few years. However, there are still con