Engineer Makes Carbon-Negative Bricks That Cut Construction Cost By 50%

Many of us focus on plantation drives and opting for environment-friendly products to reduce carbon emissions. But in the process, we tend to overlook, or are unaware altogether, that the very walls surrounding us in our homes are also massive contributors to climate change. Gravel, sand, and cement extracted from the earth and mixed together with water have created a recipe for disaster.

The problem becomes evident if we understand the process of making cement.

Raw material such as limestone and clay comes from quarries. The materials are crushed and mixed with iron ore or ash and fed to cylindrical kilns at around 1,450 degrees Celsius. The process is called calcination, which splits the mixture into calcium oxide and CO2, giving out a new product called clinker. The new marbled-sized and grey product is cooled and mixed with gypsum and limestone and sent as a ready-mix to concrete companies.

Half of the CO2 emissions from cement happen during the process. If cement were considered a country, it would become the third-largest CO2 emitter in the world, surpassing a massive country like India.

But a Roorkee and Visakhapatnam based social enterprise, GreenJams, might just have an alternative. The venture is creating carbon-negative building material from agriculture biomass and hemp blocks.

Called Agrocrete, the product is made of upcycled material and can reduce construction costs by 50%, increase thermal insulation by 50%, and cut down the time required for constructing buildings, founders say.

‘Better than a conventional brick’

Tarun Jami, co-founder and a civil engineer, says he became aware of the role of concrete in the climate crisis during his academic days. “In 2013, during my graduation, I came across the material Hempcrete and was impressed by its carbon-negative qualities and thermal capabilities. I decided to study it,” he tells The Better India.

Tarun referred to YouTube and other online resources to understand the making and characterises of Hempcrete. “I attempted to make the bricks from pure lime as well as cement by keeping hemp as a common material. Both failed catastrophically,” he says, adding that this made him realise that there was a need for detailed studies on this topic.

To dig deeper, he pursued environmental science during his post-graduation and finished his degree in 2016. He set up GreenJams in 2017, intending to create a carbon-neutral building environment in the construction industry. After research and development, he recreated Hempcrete in 2019. His father and brother Varun also joined the cause to handle operations, partnerships and legalities.

Later that year, he visited Delhi and experienced the severely affected air quality in the city. “I almost crashed my car during the trip due to smog and low visibility, and even felt affected health-wise. I researched the reasons behind this and learnt that stubble burning contributed to 44% of Delhi’s poor air quality,” he explains.

To find a solution to this, Tarun created Agrocrete, made from agricultural residue and industrial by-products. “We collect residue from farmers and chop and process it. The residue is mixed with our innovative product BINDR, a 100% up-cycled low carbon replacement of Portland cement made from industrial by-products of steel, paper and power industries. As it comes in powder form, the material also becomes useful for masonry mortar and plastering,” he says.

The product has the strength equivalent to that of a conventional red brick from the kiln, but has better thermal conductivity, less water absorption tendency, captures tonnes of carbon emissions and has a life duration of at least 75 years. “The blocks are 30% lighter, making it convenient for masons to work on. They’re also bigger, which reduces the construction time and cost of labour,” he adds.

Need for restoring the environment

To test, demonstrate and display, Tarun used the material to build a 1,100 sq feet load-bearing structure to extend his office space into a manufacturing unit at Roorkee. “We built it for Rs 1.95 lakh, as against the Rs 5.5 lakh that would have been required if we used conventional materials. It also captured 3.1 tonnes of CO2 emissions in the process, making it a carbon-negative building,” Tarun says.

Neetu, a mason who worked on the project, says, “The BINDR felt like normal plaster but was more convenient to apply and smoother in its finish. Using the material did not cause any irritation on the skin.”

Tarun says that using the big blocks is easy and gives a cleaner finish with fewer mortar joints. “We finished the work in about four days, which otherwise would require 10-12 for the same amount of construction,” he says.

The social enterprise has already bagged two clients and has been selected for the MassChallenge Switzerland 2021 Accelerator Programme.

Rajvir Rathi, Tarun’s first client, says he decided to choose the construction material for his standalone house due to sustainability reasons. “I believe that we should switch towards an environment-friendly lifestyle and want to support startups working towards it. The technology is new, and I felt like giving it a try for my one-story house in Surajgarh,” he says.

Meanwhile, Tarun says, “It is about time we repair the damage done to the environment and restore ecosystems for the well-being of the planet, and subsequently humans. We need to start thinking in terms of life cycle impacts and find alternatives beyond the concepts of the circular and linear economy,” he adds.

To seek more information on GreenJams, click here.

Edited by Divya Sethu