Nappies added for green builds
An infantile approach could drive new, sustainable building materials.
Up to eight per cent of the sand in concrete and mortar used to make a single-story house could be replaced with shredded used disposable nappies without significantly diminishing their strength, according to a study published in Scientific Reports.
The authors suggest that disposable nappy waste could be used as a construction material for low-cost housing in low- and middle-income countries.
Disposable nappies are usually manufactured from wood pulp, cotton, viscose rayon, and plastics such as polyester, polyethylene, and polypropylene. The majority are disposed of in landfill or by incineration.
In a recent project, researchers prepared concrete and mortar samples by combining washed, dried, and shredded disposable nappy waste with cement, sand, gravel, and water. These samples were then cured for 28 days.
The experts tested six samples containing different proportions of nappy waste to measure how much pressure they could withstand without breaking.
They then calculated the maximum proportion of sand that could be replaced with disposable nappies in a range of building materials that would be needed to construct a house with a floor plan area of 36 square metres that complies with Indonesian building standards.
The authors found that disposable nappy waste could replace up to ten per cent of the sand needed for concrete used to form columns and beams in a three-story house.
This proportion increased to 27 per cent of sand needed for concrete columns and beams in a single-story house.
Up to 40 per cent of the sand needed for mortar in partition walls can be replaced with disposable nappies, compared to nine per cent of the sand in mortar for floors and garden paving.
Together, up to eight per cent of the sand in all of the concrete and mortar building materials required to build a single-story house with a floorplan of 36 square metres can be replaced with disposable nappy waste - equivalent to 1.7 cubic metres of waste.
The authors note that wider implementation of their findings would require the involvement of stakeholders in government and waste treatment in developing processes for the large-scale collection, sanitising, and shredding of nappy waste.
Additionally, building regulations would need to be modified to allow the use of diaper waste as a construction material.
Used nappies are also gaining traction as a fuel source.