A total of 76 major disasters took place across India due to breaching of ash ponds damaging crops, inundating villages and causing property as well as human loss, during 2010-20, according to the ‘Coal Ash in India’: A compendium of Disasters, Environmental and Health Risks, brought out by the Chennai-based Healthy Energy Initiative India. “Unfortunately, this had happened though there is technology to prevent such disasters.
Fly ash is the most hazardous and disaster-prone product, and the only befitting solution is to put 100% of the product, generated by Thermal Power Plants (TPPs), to value added applications in order to avoid accumulation in ponds,” say N. Kalidas and N. Bhanumathidas of the Visakhapatnam-based Institute for Solid Waste Research and Ecological Balance (INSWAREB).
Nano Concrete Aggregate (NACA), developed by INSWAREB has been chosen as one among the top 10 innovations from India for presentation at the Global Platform for Disaster Risk Reduction, to be organised by United Nations office for Disaster Risk Reduction(UNDRR) at Bali, Indonesia, from May 23 to 28.
“In concrete mix, the general ratio used is 1:2:4 for cement, sand and stone respectively. This shows that stone is the highest proportion used. Only about 60% of the 250 million tonnes of fly ash, being generated by Thermal Power Plants (TPPs) in India, is being used by the construction industry, while the remaining is being dumped in ash ponds and on open ground, causing disasters,” Mr. Kalidas told The Hindu.
“While 81 million tonnes of fly ash is being consumed by the construction industry for making brick and other products, the remaining 40% of fly ash, is causing the disasters. NACA provides a huge opportunity to provide zero dumping. Once that is exhausted old dumps in ponds can be excavated and put to use,” he says. “We sent videos of our presentation to the jury and the selection committee understood our commitment and chose our innovation among the top 10 from India. NACA was innovated by INSWAREB, and after executing a couple of structures as field demonstrations, this invention was patented in 2010. It can totally substitute natural stone aggregate (NSA) for cement concrete applications,” says Mr. Kalidas.
“The engineering studies on NACA concrete proved that NACA can replace natural stone aggregate (NSA) for developing concrete up to 40-60 MPa (double the strength of concrete that is used conventionally for slabs). This invention has bagged the 1st prize at the National Grand Challenge conducted by NTPC in 2019 for innovative ideas of mass scale fly ash utilisation,” he says.
