In developing countries in Asia, governments are desperate to reduce construction costs in light of their growing populations. Indonesian masons are testing a concrete where the sand is partly replaced by disposable diapers. And it works !
Researchers from Japan’s Kitakyushu University have been working on the project for years. They seek to incorporate recycled products into conventional concrete. It’s good for the environment and lowers construction costs. And they tested making walls out of disposable layers. Concrete made from leftover baby diapers works. The little house stands upright, is waterproof and has the same physical properties as a normal house.
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Of course, these layers are treated first. They are washed, passed through sodium chloride, dried and then shredded. These small pieces of layer are then added to the other materials that are used to mount the walls. They are mixed with sand, cement and gravel to make very strong concrete.
The ideal “recipe” saves up to 40% sand
The engineers tested different proportions to find the ideal recipe. And roughly, the remains of layers can replace up to 10% of the volumes of sand that are usually used to make load-bearing walls. And for interior partitions, you can replace up to 40% of the sand with your layer leftovers. On paper, this saves money on the cost of materials.
And the big advantage is that we have an abundance of raw materials. The figures are indeed staggering: 300,000 diapers are thrown away every minute worldwide, according to calculations by the Association of Biodegradable Industries. Each year, the world population consumes 167 billion diapers. And almost all ends up either in giant landfills or in incinerators that generate a lot of CO2.
Environmentally friendly recycling
This is also why there is a lot of research on the future of these diapers which are very difficult to recycle. They contain cotton, viscose and lots of different plastics. The Kitakyushu researchers explain that their large-scale reuse in construction could really be interesting for developing countries. But it would be necessary to set up a chain of collection which does not exist for the moment.
Apart from disposable nappies, researchers are testing other recycled products such as glass powder which could be incorporated into cement. There are also avenues of work with agricultural products, in particular, the rice husk is the first skin of the grain of rice, before it is husked. Now dried, this skin is also tested in slightly more organic building materials.