Study on the use of raw materials: diaper waste for house construction

Scientists have investigated how used diapers can be recycled as an admixture for concrete. An idea with potential.

There is actually a diaper admixture in the concrete of this shell Photo: picture alliance/dpa/Springer Nature | Anjar Primasetra

What is really harmful to the climate? Concrete, used for example to construct buildings: Various calculations quantify the CO₂-Emissions in the area to around 10 percent of the emissions caused worldwide. And what else is really harmful to the climate? disposable diapers. The child, wrapped in disposable material for an average of 2.5 to 3 years, and – boom! – according to a British study from 2008, around 550 kilograms of CO₂-Equivalents emerged. And all that without flying, driving or binging on Netflix.

So what if you replaced one of these two climate-damaging things with the other, thereby saving emissions? No, no concrete diapers, that probably wouldn’t make it better for a bunch (sorry) of reasons. But: houses made of used diapers.

Now before anyone holds their nose: For those in the specialist magazine Scientific Reports For the published study, the researchers used used disposable diapers as a basis, but they were washed, disinfected and shredded in their aggregate state. The result: For a one-story house, the diapers in the load-bearing parts could replace up to 27 percent of the sand in the concrete and up to 40 percent of the sand in the mortar. Because the authors of the study refer to the building standards in Indonesia, the proportion in other countries could be correspondingly higher or lower. Assuming these values, however, around 1.7 cubic meters of diaper waste could be used for a 36 square meter house with a building material requirement of almost 23 cubic meters.

The authors not only calculated for the study, but also experimented. They made concrete mixes with different percentages of diaper instead of sand. They allowed the mixtures to cure and tested their compressive strength after 28 days to find out what percentage of diaper was acceptable to achieve the strength required for house building. For example, adding 1 percent diaper to the concrete improved curing and resulted in the “strongest and most durable” material. Up to 5 percent admixture would have resulted in the highest strength in the 28-day check.

With a view to Indonesia, the authors of the study were primarily concerned with showing a way in which the scarce building materials can be used efficiently in view of the increasing demand for living space and waste can also be sensibly recycled. However, the concept also has potential for applications in which concrete is absolutely necessary for a building.

Now the challenge remains: checking whether the local building regulations allow an admixture. And then find a company that produces concrete with diaper content.