Pervious concrete is a type of light-weight concrete made by omitting fine aggregate in design and
batching. This makes a concrete with large, continuous and interconnected pore-system in the
concrete, through which water is conducted. The pervious concrete made is lighter, less dense, less
strong, more porous and more permeable than the convectional concrete. It is thus ideal for
managing storm water.
In this research, an ideal mix formula was sought with acceptable characteristics to use in drainage
channels to manage storm water in urban centres, while also recharging the town’s constrained
aquifers. The ratio found most ideal was 3:1:0.375 for aggregates, cement and water respectively.
The pervious concrete made had a density of 1999.4 Kg/m3 and average compressive strength of
18.63N/mm2. On the other hand it had an average porosity of 23.84% with seepage rate or
permeability of 0.0102l/s. The pervious concrete mix design obtained was thus able to strike a
compromise and obtain optimal values between strength and porosity which are equally paramount
yet have inverse relationship.
In terms of addressing the devastating state of many town’s storm water, laboratory results showed
that 34.72% of the storm water in drainage channels, could be seeped to the ground below the
drainage if they were made of pervious concrete. This would ease the effects of flooding in the
city and also recharge aquifer to serve boreholes. The pervious concrete made, was also found to
have stiff consistency which is advantageous in placing since it would not segregate if dropped
from higher height.