BHUBANESWAR : In a novel urban solution, researchers at IIT Bhubaneswar here have developed pervious concrete pavements, a substitute to bituminous and concrete ones, that will help combat urban flooding and heat island effect in cities.
According to the researchers of the School of Infrastructure at the institute, widespread construction and use of impervious pavements like bituminous and concrete surfaces exacerbate storm water runoff during rainfall, causing flood-like conditions in cities. Additionally, these have led to significant depletion of groundwater reserves.
Recognising the issue, the researchers have come up with pervious concrete pavements with the objective of curbing storm water runoff and promoting groundwater recharge. Unlike traditional pavements, pervious concrete features interconnected voids with at least 15 per cent porosity, allowing storm water to percolate through the pavement and recharge the groundwater.
As part of the experiment, IIT-BBS used pervious concrete pavements in the cycle parking area, covering 150 square metre with 18 slabs produced at a ready-mix concrete (RMC) plant. Students from the Transportation Engineering section participated in it, placing 150 mm thick pervious concrete slabs of 3.5X2.5 metre over a 250-300 mm reservoir layer atop the subgrade. The system was found capable of storing over 20 cubic metre of water without runoff.
To assess pervious concrete pavements’ efficiency, rainfall data of June 27 was also obtained from the GMAG lab of the School of Earth, Ocean, and Climate Sciences. It was found that the pavement infiltrated 6.8 cubic metre of storm water per hour during 47.24 mm/hr rainfall from 1.30 pm to 4.00 pm without any runoff.
Anush K Chandrappa, a faculty in the School of Infrastructure, said their findings demonstrate that these pavements not only reduce runoff but also mitigate urban heat island (UHI) effects due to their increased porosity and latent heat flux. During the summer season at IIT Bhubaneswar, the surface temperature of bituminous pavement was approximately 20°C higher than that of pervious concrete pavement.
The project received extensive support from head of the School of Infrastructure at IIT Bhubaneswar Prof Sumanta Haldar.