CHENNAI: One of the pitfalls of growing demand for housing and urban space is the mounting construction debris. Disposal of construction and demolition waste is emerging as a major challenge and posing environment hazard.To address this problem, a group of students from a private engineering college in Erode has come up with a novel technology through which low-cost bricks can be produced by recycling the construction debris. The idea has found merit with IIT Madras, which has decided to incubate the company. Chennai generates close to 1,200 tonnes of construction debris per day and less than 1% is recycled. The students are from Kongu Engineering College and had emerged as finalists in the Carbon Zero Challenge organised by IIT Madras recently.
Initially, two students — M Diwakar and V Balakarthikeyan — had developed the technology mentored by their professor GS Rampradheep. Now, four new students have joined the initiative as the idea is being viewed as a good commercial venture. Corporate giants like Godrej and Tata Steel are keen on using this technology to recycle their waste. Rampradheep told Express that debris has been recycled into construction material such as bricks and interlocking pavers. “We have tested the bricks for density and durability in 12 nationally reputed institutes and results showed that they are stronger and more durable than conventional bricks and concrete blocks.”
On feasibility, the professor said the conventional paver block costs `15, but the recycled block would cost as low as `1.50. “Our technology is economically viable. Godrej and Tata Steel have given us concurrence to visit their plants in Mumbai and Jodhpur to sample their waste and recycle it using our technology.” On the process, the students’ team said the debris is sourced from construction sites and broken down into particles of different diametres. The particles are then powdered down by a pulverising machine. The crushed material is then mixed with sodium silicate, which will act as an agent to reduce porosity, increase durability and help the material bind well.
The mixture is then put through carbonation process where carbon dioxide is injected into it and then mixed with cement and water and moulded into blocks. They are sprayed over the sand brick and kept under direct sun light for 24 hours to enhance the tensile strength. Injection of CO2, which is primarily taken from the industries, will help improve the physical properties including the density of the aggregaten,” said Rampradheep. The team has applied for patents for both technology and equipment used.