In Nairobi, waste collection systems are almost non-existent and the recycling rate of plastics is very low, while 500 tonnes of plastic waste are thrown away daily: much of this waste ends up in the environment and in landfills.
Environmentally-friendly paving stones
After witnessing the pollution caused by the plastic bags littering the streets of her home town, Nzambi Matee, a materials science graduate and former engineer in the Kenyan oil industry, came up with the idea of using this rubbish as a resource and using it as a raw material for making new products. And that new product is a brick that she created after several trials and long months of work by mixing high-density polyethylene, low-density polyethylene and polypropylene waste with sand.
“Building differently, building affordably, building sustainably” – that is Gjenge Makers’ motto.
To achieve this, the waste that she has recovered before it ends up in landfill or that is supplied by recyclers or factories is first crushed, then sorted by colour and finally mixed with sand and pigment. The resulting mixture is then heated to 350° in the machine designed by Nzambi, then moulded and compressed. Every day, up to 1,500 paving stones, paving slabs or bricks are produced and sold at an affordable price - between 6 and 10 Euros per m², depending on their colour and thickness.
“Almost five to seven times stronger than concrete” but lighter than traditional materials, Gjenge paving is fully certified by the Kenyan Bureau of Standards (KEBS). Ideal for wall construction, paving and other construction needs, it is now used in Nairobi's school walkways and municipal car parks, as well as in hotels and luxury residences won over by its durability, appearance and attractive price.
Building greener with plastic waste
The woman who began experimenting with her mixes in her mother's small garden in 2017 has to date recycled more than 20 tonnes of plastic waste. Her start-up now comprises a team of 110 people and plans to invest in another, larger production line that could triple its capacity.
In addition, Nzambi Matee is one of seven young entrepreneurs developing environmental projects around the world to have received the "Young Champions of the Earth 2020" award from the United Nations Environment Programme (UNEP) in December 2020. She is the only African person among the winners.