Researchers from the University of Kitakyushu, in Kitakyushu, Japan, have determined that used disposable diapers can be transformed into a replacement for sand in concrete and mortar.

The researchers project that in the future an average small single-story house could potentially see roughly 8% of the sand in its construction replaced with processed used diapers — and reportedly without compromising the structural integrity of the build.

Source: Siswanti Zuraida et al.

The benefits of this process, according to its developers are two-fold: it could be used to construct low-cost housing and it could divert discarded diapers from the landfill.

To create the new concrete and mortar mix, diapers, which are generally composed of wood pulp, cotton, viscose rayon, and plastics like polyester, polyethylene, and polypropylene, are washed, dried, shredded and then combined with cement, sand, gravel and water. This mixture is then left to cure for roughly 28 days.

In the lab, six different samples with varying concentrations of diaper waste were tested to measure the amount of pressure each of the mixtures could withstand without breaking.

The team determined that for a three-story house, up to 10% of sand can be replaced with the diaper mixture to create columns and beams. In a single-story house, the proportion can reportedly increase to 27%. Further, disposable diapers can potentially be used to replace up to 40% of the sand used in the manufacture of mortar in partition walls, while just 9% of the construction material could be used in the creation of floors and garden paving.

In total, the researchers reported that an estimated 8% of sand in all concrete and mortar materials required for the construction of a 388 ft² single-story house can be substituted with the disposable diaper waste mixture.

An article detailing the process, “Application of non-degradable waste as building material for low-cost housing,” appears in the journal Nature.