A research project led by the University of Bath in partnership with colleagues from Goa Engineering College has found plastic bottles could play a part in the construction of new buildings – a move that could also help tackle India’s growing waste problem.
The researchers say waste plastic has the potential to be used as a partial replacement for sand in structural concrete. By replacing sand with similarly sized and shaped waste plastic particles from ground up bottles, they found they could make concrete that was almost as strong as conventional mixes.
Sand typically accounts for 30 percent of a concrete mixture. Substituting just 10 per cent of sand in a conventional concrete mix with plastic could not only be beneficial to the environment but also save 820 million tonnes of sand a year.
Plastic waste has become a major problem in India over recent years, with an estimated 15,000 tons dumped in the streets everyday. In addition, the scale of economic growth in the country has resulted in a booming construction sector, leading in turn to a national sand shortage.
Yesterday, the research paper – Performance of structural concrete with recycled plastic waste as a partial replacement for sand – was chosen by an international scientific committee to receive the Atlas Award, in recognition of its potential global impact.
Principal investigator Dr John Orr said: “Typically, when you put an inert, man-made material like plastic into concrete, you lose a bit of strength because the plastic material doesn’t bond to the cement paste in the material in the same way that a sand particle would.
“The key challenge here was to have a limit between a small reduction in strengths, which we achieved, and using an appropriate amount of plastic to make it worthwhile. It is really a viable material for use in some areas of construction that might help us to tackle issues of not being able to recycle the plastic and meeting a demand for sand.”
Main image: © University of Bath 2018