BENGALURU:A group of civil engineering students from the CMR Institute of Technology have a solution for not just the water woes of the city, but also waterlogging during the monsoon.
The ‘pervious concrete block’ looks like an ordinary piece of brick at first glance. It is, however a special kind of concrete brick that is porous and with high permeability, made by these students.
“The concrete consists of coarse aggregate (a granular material made of gravel, crushed stone, cement and other materials) that has been treated for a period of 28 days. We used the coarse aggregate and mixed it with cement and did a compression test to understand its strength,” says Danish Akthar, a student involved in the project.
Danish further says that unlike normal bricks, the materials used in their concrete mix do
not have sand, giving the brick its special nature. “When you use sand, the pores in the concrete get mixed, thereby not giving it that distinct permeable nature,” he adds. This type of concrete is mainly used in low-volume traffic pavements such as parking lots, footpaths etc, as the compressive strength is low.
When it rains, most areas in Bengaluru are flooded. However, if these areas use the pervious concrete block to make roads and footpaths, the problem of waterlogging will be reduced as all the water will run off and go down to the water table says Danish. “This water can replenish the ground water. Trees fall in the rain because their roots, starved of water, are weak... non-porous concrete slabs cover them,” says Danish.
The students have already won the first prize at Sristhi - 2017. “The special concrete is being used in a number of cities in the west, but it has not caught on in India,” says Danish.