We have been wanting to retire traditional brick for years. This piece that has been the pivot on which civilizations have been built has ended up becoming a headache. The same thing happens to us with concrete: it is easy, cheap, but very polluting. That is why there are universities, organizations and even agencies like DARPA investigating to find alternatives. A young woman in Kenya believes she has found -another- solution: plastic.
And it is a very interesting 2×1.
plastic bricks. Nzambi Matee is a young Kenyan materials engineer who founded her company Gjenge Makers with one goal: to turn the numerous plastic waste into bricks. Whoever says bricks means any urban element such as paving stones, tiles or manhole covers.
The idea is to address the plastic waste crisis in Nairobi while trying to provide a solution to the need for affordable construction elements. And, also, giving work to women and young people belonging to vulnerable communities.
The process. To create these plastic bricks, Matee was experimenting with different formulas until he found one that achieved the right properties. To do this, it mixes the plastic with sand into a whole that is heated and compressed to form solid blocks. With the right proportions, they estimate that plastic bricks are five times stronger than traditional ones.
When that step has been completed, the mixture is introduced into an extruder where it is heated, with the plastic reaching the melting point, but without chemically degrading. The material is then poured into molds and a hydraulic press compacts to achieve both a high density and the desired shape. When it cools, it is removed from the mold and we now have a batch of bricks.
Properties. The result is a material that, according to those responsible, has good thermal resistance as it has a melting point of more than 350 degrees. For paving streets in Nairobi, this is an important detail because it ensures that it will maintain its shape under normal use. They also do not crack as “easily” as a conventional brick while maintaining some flexibility.
What uses? Well…anyone that involves the use of a traditional brick. Apart from the cases mentioned, you can also pave sidewalks, patios, parking lots or as decoration, since they can be designed in various colors.
Tackling the plastic problem. Many times we have echoed the so-called ‘neobridrillos’. There are a lot of materials, plastic being a common component to address the recycling problem, but there are also cane, for example. And we always say the same thing: they are interesting, but they cannot be used because they are not approved. The difference is that the Kenya Bureau of Standards is responsible for legitimizing use for urban and residential projects in the country, and Gjenge Makers’ plastic bricks have obtained permits.
Examples of use
The plastics they use are also those that can be left out of the recycling circuit. Kenya, with 95% of its waste recyclable, but where only 5% is recycled, is not the most committed country in the world in this sense (in fact, it is one of the great pending tasks on the planet).
And the plastics used are common: HDPE -high-density polyethylene-, LDPE -low-density polyethylene- and PP -polypropylene-. They are widely present in shopping bags, wrappers, detergent bottles, ropes, buckets and many other containers that simply end up in traditional trash. According to the startup’s numbers, since the start of the project in 2020, 200 tons of plastic waste have been used to convert it into construction material.
Beyond the brick. But something that we also often say is that it is one thing for the invention to be ready and work… and quite another for it to be consolidated as a new construction material. Because other elements such as the cost per unit or the economic interests of the traditional industry come into play there.
And something that is also important is the social impact of the company. According to its website, it provides direct and indirect employment to more than 600 people. They are linked to the collection, classification and manufacturing of the product, and a large part of the workforce is women and young people who find it difficult to participate in other economic activities.
In the end, it is a project that is located at the intersection between the circular economy, sustainable urbanism and social inclusion. And it is a nice program, but as we say, there are more and more sustainable bricks, but in the end we continue to choose the most polluting process.
Images | Thread Makers
In WorldOfSoftware | We have just reinvented the brick. It is just as it was millennia ago
