The main advantage of pervious concrete is that it reduces the
the surface of the pavement. They are restricted to areas with
generation of urban heat. It helps tree planting in parking lots
relatively low traffic volumes and relatively light vehicles, and it
and city sidewalks which offer shade and produce a cooling
may require costly maintenance if pavement becomes clogged
effect in the area. Pervious concrete pavements or sidewalks
with sediment and no longer allows infiltration.
allow adjacent trees to receive more air and water, and still permit the full use of the pavement. It absorbs, stores heat and then
Because of the above reasons, still pervious concrete requires
radiates heat back into the environment like a typical asphalt
improvements. Some of the improvements identified are the use
surface. The open void structure of the pervious pavement also
of an underground drainage system, the use of uniform gravels
allows cooler earth temperatures from below to cool the pave-
as base material to avoid trapping water, the use of silica fume,
ment. The lighter colour of concrete is beneficial from an energy-
super plasticizer, and polymer-modification to achieve a bet-
saving standpoint and since the pervious concrete is reflective,
ter strength and by allowing slopes to be less than 5-10% to
the need for lighting at night is reduced. The main advantages
facilitate infiltration rather than runoff. Conclusively, pervious
are these pavements are safer for drivers and pedestrians as they
concrete can be used as a sustainable material, but still several
reduce hydroplaning and tire spray. In some countries, parks are
improvements are required.
installed with pervious concrete pathways to provide access for
people in wheelchairs.
Although there are a lot of advantages in using pervious con-
CHATHURIKA JAYASUNDARA
crete, there are a lot of disadvantages too. Some of the envi-
Department of Civil Engineering
ronmental factors are, the rising of the water table below the
(Fourth Year)
pavement to a higher level thus preventing the precipitation
from being absorbed into the ground and migration of road
References
salt containing chlorides through the porous pavement into
1. Pervious Concrete Pavement, [online],
groundwater, that if freezes could destroy the concrete. Pervious
Available: http://water.epa.gov
pavement should not be used in sites where excessive oil, grease,
2. The Practical Application and Economic and Environmental
or other chemical deposition may lead to groundwater con-
Benefits of Pervious Concrete,[online],
tamination, such as automotive repair shops. Pervious pavement
Available: www.somero.com
types have a high potential for failure unless properly designed,
3. Concrete & Sustainable Development, [online],
constructed, maintained and it requires a proper maintenance.
Available: www.innocon.on.ca
Especially for porous concrete and asphalt paving, maintenance
4. http://www.perviouspavement.org/materials.html
includes vacuum sweeping to remove deposited sediment as
5. Karthik. H ,Pervious concrete for sustainable
well as washing with a high-pressure hose to remove clogs in
development,[online], Available: www.nrmca.org
PERVIOUS CONCRETE PAVEMENTS
ALLOW ADJACENT TREES TO RECEIVE
MORE AIR AND WATER
Source: www.hellerconcreteinc.com
Gauge Newsletter
University of Peradeniya
9