Revolutionising Affordable Housing: Recycled Baby Diapers as Concrete Composite
A prototype for low-cost housing in Indonesia using concrete composite from disposable baby diapers has been successfully built. The newly developed material has recently been tested for use in line with Indonesian building standards representing a big step in the shift to more circular materials in construction and the future of sustainable housing.
Research into the potential of non-degradable waste as construction materials has gained popularity in recent years. Successful applications of waste composites aim to reduce environmental damage on several levels; increasing the demand for otherwise worthless waste and incentivising effective recycling can decrease harmful waste deposition, replacing traditional materials with carbon-neutral or even carbon-negative alternatives can reduce project emissions and by reusing disposed of materials, affordability requirements can be met by phasing out costly new resource extraction.
The Challenges:
Developing viable materials from non-degradable waste is not a new endeavour. Over the last 20 years, the development of recycled construction materials has been gaining popularity; however, the task has faced many challenges.
- Cost factors represent the most intractable obstacle. Building materials are often the greatest expense in simple residential dwellings, particularly in developing countries. Research into housing costs in Kenya showed that building materials accounted for 40% of total housing costs. When it comes to recycled waste materials, the sourcing and processing of this waste for reuse is often expensive due to poorly adapted recycling systems. The combination of these two factors makes developing a sufficiently cheap waste composite a difficult task.
- To add to this, creating a material that can meet national building and safety standards has repeatedly prevented the application and cost-effectiveness of non-degradable composites, with many regulation boards still favouring conventional materials over locally sourced and recycled alternatives.
- Overcoming public perceptions of waste-based materials is also an ongoing battle. Traditional, less ecological options still dominate the supply of construction materials worldwide, as many still doubt the quality of newly developed waste composites.
Raising awareness of their availability and proving the viability of waste-based construction materials through successful projects is key to updating building restrictions and improving their popularity. Increased demand for such materials would also lead to better-adapted recycling systems optimised for reusing waste.
A surprising solution: Dirty Diapers:
In May 2023, a team of researchers from Kitakyushu University in Japan pioneered a method of using shredded disposable diapers to replace fine aggregate in composite construction materials. They also produced a prototype low-cost house in Indonesia using this diaper-based composite.
The composite has been rigorously strength tested at different aggregate substitution ratios to ascertain which structural components could be replaced by the new material. The testing indicated that up to 40% substitution ratios could be achieved while maintaining integrity in various structural components, from walls and flooring to plastering and insulation.
The material is particularly suitable for affordable Indonesian housing but also for other developing nations. The urban population of Indonesia is growing by 4.1% annually, and in a country with over 50% urban inhabitancy, the need for affordable housing and improved waste management is urgent.
The development of this new composite offers relief for both issues, providing an outlet for excess waste and a sustainable resource on which to develop greater access to housing. The research project has also developed an ecological and economical method of treating and sanitising diapers using sodium chloride.
This project has proved that many issues facing the practical implementation of non-degradable waste composites can be worked through. Not only can they replicate the structural integrity of more conventional materials, but they can also provide a cheaper alternative.
Considering the added environmental benefits, this diaper composite demonstrates exactly why further research into developing and applying such materials could revolutionise affordable housing and why such alternatives should be adopted more frequently.
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Check out our article on how a circular economy is essential for UK construction sector to reach net zero.