T he alarming levels of air pollution in New Delhi, mostly due to the burning of crop residue, is what got Priyabrata Rautray working on developing ‘bio-bricks’ from agro-waste.
The invention by Rautray and Avik Roy, Assistant Professor, KIIT School of Architecture, Bhubaneshwar, received a Special Recognition Trophy for sustainable housing at the Rural Innovators Start-Up Conclave 2019. The event was organised by the National Institute of Rural Development and Panchayati Raj (NIRDPR), Hyderabad.
Early days
Rautray, a PhD Scholar at IIT Hyderabad’s Design Department, who lived in New Delhi between 2007 and 2017, says, “I was practising architecture and teaching product design. I saw that pollution levels spiked especially during Diwali. So I started experimenting with agro-waste such as sugarcane bagasse, wheat straws, etc.”
Fire testing on bio-bricks
Quoting Sanjay Aswale’s paper on ‘Brick Kilns in India’, Rautray tells me how the Central Pollution Control Board (CPCB) has estimated that India has around 1,40,000 brick kilns producing 66 million tonnes of CO2 emissions. Not only do they produce harmful pollutants, the kilns produce approximately 9% of the total greenhouse emissions in India.
From the fields
Rautray went on to make blocks with lime slurry and agro by-products, and researched on markets that could benefit from such a product. “I realised that the demand for clay bricks is particularly high in the construction industry and that ‘bio-bricks’ were the answer to both issues: high demand of clay bricks and burning of agro-waste,” says the 34-year-old, who converted his work into a paper (when he joined IIT in 2017) along with Roy.
It took the duo — who also founded design firm R Square Dezign in 2011 — two years of research to develop the bio-brick, currently in a testing phase. “We’ve experimented with wheat straws, paddy straws and sugarcane bagasse, and we are going to try out other agro-waste too. The idea is to make the process of clearing the field economical for farmers so that they will cut the residue instead of burning it,” says Rautray.
The bio-bricks on display
In context
Talking of how these bricks could be possible game-changers for real estate, he says bio-bricks can be used for low-cost housing along with vertical metal or wooden columns.
Based on the flame test and load-bearing tests, they found that these bricks are not only good insulators, but are also fire retardants. “However, we realised these bricks have low load-bearing strength compared to traditional bricks. Thus, they can be used in partition walls and column beam structures and not traditional load-bearing construction,” says the architect.
The bricks have to go through more testing and evaluation stages. “We are looking for government assistance for advance testing in areas where crop burning is a major issue,” he says.
By 2020, the duo plans to build a sample house with bio-bricks. “The goal is to create a process where agro-waste can help sustainable housing. Bio-bricks will be the same as traditional clay bricks.”
