Written by Rebecca Cairns, CNN
Although we are surrounded by millions of them every day, most of us don't think about bricks too often. For thousands of years, the humble brick fired with clay has not changed. The building blocks of modern suburban houses would be familiar to the planners of ancient Babylon, the masons of the Great Wall of China or the builders of St. Basil's Cathedral in Moscow.
But brick as we know it causes significant environmental problems, using raw and finished materials and creating carbon emissions. This is why Gabriela Medero, professor of geotechnical and geoenvironmental engineering at the Heriot-Watt University of Scotland, decided to reinvent it.
Originally from Brazil, Medero says she was drawn to civil engineering because it gave her passion for math and physics a practical outlet. Realizing the sustainability issues in the construction industry, she started looking for solutions. With the support of his university, Medero partnered with his engineer colleague Sam Chapman and created Kenoteq in 2009.
The company's flagship product is K-Briq. Made from over 90% construction waste, Medero says K-Briq - which doesn't need to be baked in an oven - produces less than a tenth of the carbon emissions of conventional bricks. As the company tests new machines to start increasing production, Medero hopes its bricks will help build a more sustainable world.
The problem with bricks
Although they are made from natural materials, there are problems with bricks at every stage of their production.
Bricks are made of clay - a type of soil that is found all over the world. The extraction of clay removes the fertile topsoil from the earth, inhibiting plant growth.
In conventional brick production, clay is shaped and fired in ovens at temperatures up to 1,250 ° C (2,280 ° F). The majority of brick kilns are heated by fossil fuels, which contribute to climate change.
Once made, the bricks must be transported to construction sites, which generates more carbon emissions.
Globally, 1,500 billion bricks are produced each year. Positioned end to end, they would stretch to the moon and retreat 390 times.
The environmental footprint of the different bricks reflects several factors, including the type of oven, fuel and transportation. But with so many products, their impact adds up, says Medero.
Enter the K-Briq. To do this, construction and demolition waste, including bricks, gravel, sand and plasterboard, is crushed and mixed with water and a binder. The bricks are then pressed into custom molds. Dyed with recycled pigments, they can be made in any color.
Earlier this year, Kenoteq won its first order - to supply bricks for the 2020 Serpentine Pavilion at Hyde Park in London (although the project was postponed to the summer of 2021 due to the current pandemic). Designed by the architectural studio Counterspace, the building will incorporate K-Briqs in gray, black and 12 shades of pink. The Pavilion's main architect, Sumayya Vally, says that as a recycled product, the K-Briq called on her. He "embodies" the past through his use of old materials, she says, adding that because bricks can be customized, they allow "the designer to be part of the process of building the material", creating unique opportunities in architecture. .
Why can't old bricks be reused?
In the UK, around 2.5 billion new bricks are used in construction each year - and about the same number of old bricks are demolished. A seemingly simple solution to the problem of brick production would be to reuse old bricks.
But it is not that simple. According to Bob Geldermans, a researcher in climate design and sustainability at the Delft University of Technology in the Netherlands, recovering bricks is an expensive and "labor-intensive" process.
According to the Brick Development Association of the United Kingdom, old brick structures must be carefully dismantled and bricks cleaned from the mortar with hammers and scissors. The recovered bricks are used to help renovate historic buildings or for other specialized projects, but for mass construction, the process is too costly.
An additional obstacle is that there is no standardized way of verifying the strength, safety or durability of the bricks recovered.
Medero says K-Briqs could solve both of these problems.
According to Medero, the K-Briq will be at a price comparable to conventional bricks. In addition, as a new product, K-Briq has been subjected to a rigorous evaluation in the materials testing laboratory of Heriot-Watt University and certified by the BBA (British Board of Agrement). Medero claims that K-Briqs are stronger and more durable than baked clay bricks, and also offer better insulation.
Scaling
Kenoteq currently operates a workshop in Edinburgh, which can produce three million K-Briqs per year. Medero plans to scale up - but it's hard to create a construction revolution.
Geldermans says the industry is notoriously slow to change - adding that legislation is often far behind innovation, so that construction companies are not encouraged to adopt sustainable materials and practices.
Stephen Boyle is the program manager for the non-profit construction Zero Waste Scotland who, along with organizations such as Scottish Enterprise and the Royal Academy of Engineering, has provided Kenoteq with funding. He attributes the conservatism of the industry to a "chicken and egg" situation. Innovative startups need big contracts to enable them to grow, he says, but have trouble becoming competitive without a large operation already in place.
But despite the challenges, Kenoteq is far from the only company trying to make construction more sustainable. Other innovators include Qube, a start-up based in India which creates bricks from plastic waste, and ClickBrick which eliminates the use of cement thanks to modular stacking (think of real Legoes).
There are signs of change. In Scotland, the government is considering a circular economy bill that encourages businesses to think creatively and economically about how they reuse and recycle materials. Boyle says there are "entrepreneurs who would use [K-Briqs] tomorrow ", if they were produced on a large scale.
Over the next 18 months, Medero plans to install K-Briq machines on-site in recycling plants. This will increase production while reducing transportation-related emissions, she says, because trucks can collect K-Briqs when they drop off construction waste. "We must have the means to build sustainably, with affordable, good quality materials that will last."
