Disposable diapers and concrete are both harmful to the environment, but Japanese researchers believe that using diapers for create concrete could solve part of this problem.
Could dirty disposable diapers be reused to create sustainable housing? It’s not a question most people would ask, but a team of engineers from Japan’s Kitakyushu University have an answer: Yes, it can.
Of course, the other question is whether anyone would actually want to live in a house made out of diapers.
As Gizmodo reported, the team was able to successfully replace some of the sand in conventional concrete with dirty layers, and according to their estimates, around eight percent of the sand and mortar needed to build a house one-story could be replaced with jagged. layers without affecting stability or strength.
They published their findings in the journal Scientific Reports and detailed the process for collecting, cleaning and reusing the soiled diapers. As lead researcher Siswanti Zuraida told Gizmodo, the team processed each of the layers “manually.”
They removed all solids from the soiled diapers by washing, then neutralized the remaining “offending agents” with a chemical soak, Zuraida explained. Once cleaned, the researchers dried and shredded the layers, then added them to a concrete mix.
The team created and tested six different mixes with varying ratios of concrete to layers, focusing on both the microbial content of each and their ability to withstand various forces. According to their research, coated concrete did not contain more harmful microbes than traditional concrete, nor was it significantly weaker when used in construction.
For non-load-bearing walls, the team estimated that up to 40% of the sand used in the concrete could be replaced by shredded layers, up to 10% for the columns and beams of a three-storey house and up to 27% for the columns and beams of a one-story house.
To really put this to the test, engineers actually built a tiny one-story house in Indonesia in which eight percent of all concrete had its sand replaced with shredded layers.
The idea may seem strange, but it is actually a double environmental benefit. It eliminates common, slow-degrading items like diapers from landfills and reduces the amount of destructive sand mining needed to make concrete.
To put this into context, each year in the United States alone, approximately 4.1 million tons of diapers are thrown away. It’s even worse in areas outside of the United States, like Indonesia, which don’t have such strong waste management infrastructure.
There is also a cost advantage. As Zuraida explained, “The recycling process that is available [for diapers] is limited to developed countries because [the technology] is difficult to apply and expensive. It is therefore important to provide low-cost recycling treatment for diapers in developing countries.
Additionally, many Indonesian cities also face a shortage of affordable housing, and such housing is inexpensive to build.
But not everyone is convinced that reusing dirty layers for concrete is a good idea.
“I know diapers are a really big waste problem, but I would never use them in concrete, that’s for sure,” Dr. Rackel San Nicolas told ABC News. “I just can’t imagine how it would be used.”
San Nicolas is researching sustainable building materials at the University of Melbourne in Australia and acknowledged that there are also a number of regulations in the country that would prevent the use of ‘layers’ in concrete.
But San Nicolas said there are already other ways concrete makers can replace aggregate and cement themselves with waste to make concrete more durable.
A notable substitute is fly ash, a by-product of coal combustion, which can be replaced with cement and also helps reduce CO2 emissions.
“We test and try to [prove] more applications where we can’t use any cement, where there’s just fly ash – basically cementless concrete,” San Nicolas said.
There’s also scale to consider, Zuraida admitted. It’s one thing to construct an isolated one-story building out of ply concrete, but it’s quite another to extend this process to the entire infrastructure of the city.
“Unfortunately, at this scale, the research has not yet involved waste management and other stakeholders,” Zuraida said.
It would take a ton of planning and work to gather a massive amount of dirty diapers, clean them, and turn them into durable building materials, and at this point, that process hasn’t even begun.
Zuraida and his team remain optimistic, however, and plan to move forward with the idea, both improving their methods of collecting and processing the layers, as well as analyzing the concrete in the layers for thermal properties and acoustics to ensure it would be suitable for the accommodation.
After reading this curious new study, find out how other countries are trying to tackle climate change, like New Zealand’s proposed tax on cow farts. Or explore this eco-friendly ‘hobbit house’ in Wales.