A Kenyan materials engineer has found a way to help the environment by turning plastic waste into sustainable building materials that are stronger than concrete.
Nzambi Matee, a materials engineer and entrepreneur, founded Gjenge Makers Ltd. in Nairobi, Kenya. The factory collects plastic waste from commercial facilities and uses them to create bricks that can hold twice the weight threshold of concrete.
Plastic waste pollution has become a severe problem in the capital, and Matee hopes that her company can provide solutions that will help mitigate this dilemma.
“Plastic is a material that is misused and misunderstood. The potential is enormous, but it’s after life can be disastrous,” Matee told UNEP.
According to a study, 50% of cattle near urban locations in Kenya were found to have plastic in their stomachs. To address this problem, the Kenyan government prohibited the use of plastic bags in 2017. They also outlawed the use of all single-use plastic in protected natural areas in 2020.
While these bans have been helpful, they only address the problem of consumer single-use plastic. Commercial waste remains to be a deep-rooted issue within the entire country.
Matee got “tired of being on the sidelines,” so she decided to tackle the problem of commercial plastic waste on her own. With a career in materials engineering, the 29-year-old entrepreneur designed a system that converts shredded plastics combined with sand into bricks.
These components are compressed and heated in a hydraulic machine—which Matee also designed—to produce an extremely durable and sustainable alternative to concrete. The plastic bricks are lighter than the concrete ones, but they are flexible, tough, and have a higher melting point.
Matee is proud to say that their current line of pavers and bricks are five to seven times stronger than concrete.
While she usually buys plastic from recycling companies, she also receives free shipments of plastic waste from local packaging factories. The bricks are made of plastic originally used for milk and shampoo bottles, buckets, cereal bags, sandwich bags, flip-top lids, and ropes.
“There is that waste they cannot process anymore; they cannot recycle. That is what we get,” Matee said.
The Gjenge Makers factory can produce up to 1,500 bricks each day in different thicknesses and colors.
The company’s pavers can be used for both residential and commercial purposes. Their heavy-duty 60 mm paver is strong enough to be used for parking lots and highways, while their light-duty 30 mm paver is good enough to be used for walkways and household patios. The latter is two times stronger than concrete and comes in different colors.
Although Gjenge Makers was founded only recently, it has already recycled over 20 tons of plastic waste since 2017. It has also made an economic impact in Nairobi, providing 112 jobs for garbage collectors, youths, and women.
These bricks are also one of the more affordable options in the market. Each brick costs approximately $7.70 per square meter, which is far cheaper than the $98 per square yard of concrete sold in the United States.
Matee has a material science degree and previously worked in Kenya’s oil industry as an engineer before quitting her job to found Gjenge Makers.
The materials engineer says the journey to building her company and sustaining its operations hasn’t been easy. But it was all worth it.
“I jumped in, off a cliff without even a parachute. I was building it as I was falling down. But isn’t that how great things are done?” she said.
Matee plans to add a bigger production line that will triple the factory’s capacity. She hopes to break even by year-end.
Watch the video below to see how Gjenge Makers turns plastic waste into bricks.
With brilliant innovators like Matee in our midst, we might someday be able to eradicate the global plastic pollution crisis!