May 24, 2023, 3:13 am | Read time: 3 minutes
Houses made from used diapers? What sounds bizarre could replace raw materials and also relieve the environment. A study has calculated how much sand could be saved by using diapers.
In the search for eco-friendly building materials, scientists have turned to used diapers. Washed, disinfected, and shredded, they could replace up to 27 percent of the sand in concrete and up to 40 percent of the sand in mortar for load-bearing parts of a single-story house, writes a research group led by Siswanti Zuraida from Kitakyushu University (Japan) in the journal “Scientific Reports.” The calculations were based on building regulations in Indonesia.
Why Diapers Could Be Worthwhile as Building Material
“Building materials are often the most significant material contribution in the construction of homes and can account for up to 80 percent of the total value of a simple house,” the authors write. Costs are the first barrier to sustainable construction in low- and middle-income countries. Due to the annual population growth of 4.1 percent, about 780,000 new housing units are needed per year in Indonesia, but the construction industry can only produce a maximum of 500,000.
Therefore, Zuraida and colleagues tested an alternative building material with the used diapers, which would also relieve landfills. They created concrete mixtures with various proportions of diapers instead of sand. The mixtures were allowed to cure for 28 days, and their compressive strength was then tested. Based on Indonesian building regulations, they determined which parts of the house could incorporate what proportion of diapers without losing the required strength.
Diaper Content in Mortar Up to 40 Percent Possible
In a three-story house, the compressive strength of load-bearing elements, such as columns and beams, must not fall below 20 megapascals.
Therefore, the fine aggregate content can be replaced by diapers up to a maximum of 10 percent. In a two-story house, it can be up to 19 percent, and in a single-story house, up to 27 percent. In non-load-bearing masonry walls, the diaper content in the mortar can rise to 40 percent. In the mortar for floor slabs, inside the house or on the terrace, diapers can replace up to 9 percent of the sand.
Related: Japanese researchers develop building material from vegetable waste–it’s harder than concrete
Zuraida and colleagues calculated that for a 36-square-meter house with a material requirement of 22.79 cubic meters, 1.73 cubic meters of diaper waste could be used. However, this is not easy to implement in Indonesia. On the one hand, there are currently no companies there that use disposable diapers as recycling material. On the other hand, the country’s current building regulations oppose the use of diapers in concrete and mortar.
with material from dpa