Government building rules and regulations can be outdated and flawed, insisting on conventional building materials with prices incompatible with building affordable housing. Building codes proposed by the United Nations decades ago often prohibit the use of local, cheaper, and friendly materials.
Recently, some researchers have speculated that they could solve two problems plaguing developing cities—a glut of non-biodegradable waste and a scarcity of building materials—by folding the former into later on. Now, a team in Japan reports that used, sanitized disposable diapers can be incorporated into concrete and mortar, still meeting Indonesian construction standards. Affordable housing is much needed there as the urban population continues to grow and housing is scarce. Obviously, all the people who move to the cities also bring a lot of garbage there.
Diapers are replaced by fine aggregates which are commonly used in concrete making. The team determined that mortar for structural components, such as load-bearing walls and public road pavement, can only tolerate a maximum of 10 percent additional material in the liner. But mortar and concrete for non-structural components, such as non-load-bearing wall partitions and pavers with minimal impact on the floor, can allow up to 40 percent of their aggregates to be exchanged for of diaper material.
Currently, facilities for recycling dirty diapers are only available in developed countries. In this study, the diapers were washed, dried, and disinfected with sodium chloride. (Maybe because most gut bacteria can’t survive high salt levels?) Biological oxygen demand tests show that concrete made with used diapers has the same amount of microbes as concrete made from clean diapers.
Cleaning the diapers and adding them to the concrete is a better option than burning them, which is what usually happens today. Hopefully, industrial farmers will notice and try to solve their twin problems of toxic manure lakes in areas where animals are raised and the need to use synthetic nitrogen fertilizers where the plants are grown.
Scientific Reports, 2023. DOI: 10.1038/s41598-023-32981-y