This project involves turning single use plastic into light weight aggregate ("stones") for concrete. Besides the reuse of plastic, this aggregate makes the concrete light weight which makes it more useful in building structures. It also means that it costs less CO2 to transport the concrete/aggregate to the construction site.
While this initiative does not eliminate single use plastic, it is giving single use plastic a second life (which I guess means it is no longer single use).
This is also important because there is a lot of single use plastic both clogging up the environment and continuing to be made. Realistically speaking it will not disappear overnight.
While there is a lot of work done voluntarily and with public money to clean up plastic waste in the environment we need to find financially viable and environmentally sustainable uses for this material. This idea uses the circular economy principle of "Waste equals food".