Recycled plastic is already used to make some products, such as guttering and sewage pipes. Now, attention is turning to roads. On September 11th in Zwolle, a town in the Netherlands, a 30-meter bicycle track made from 70 percent recycled plastic and the rest from polypropylene was opened. It will be used to test a product called PlasticRoad, which is being developed by two Dutch firms—KWS, a road builder, and Wavin, a firm that makes plastic piping—in partnership with Total, a French oil-and-gas firm.
PlasticRoad is prefabricated in a factory as modular sections. The sections are then transported to the site and laid end to end on a suitable foundation, such as sand. Because these sections are hollow, internal channels can be incorporated into them for drainage, along with conduits for services such as gas and electricity. For the Zwolle project, sections that were 2.4 metres long and 3 metres wide were used. These were fitted with sensors to measure things such as temperature, flexing and the flow of water through the drainage channels. A second pilot cycleway is being built in the nearby town of Giethoorn.
If all goes well, the inventors hope to develop the idea and make the sections entirely from recycled plastic. Paths, car parks and railway platforms could follow. Eventually, sections for use as actual roads are planned. These could contain sensors for traffic monitoring. In time, the circuits in the plastic roads might extend to assisting autonomous vehicles and recharging electric cars wirelessly.
Prefabricated plastic roads should last two-to-three times longer than conventional roads and cost less, the companies claim, mainly because construction times would be reduced by almost two-thirds. Anti-slip surfaces could be incorporated, too, including crushed stones which are traditionally used to dress road surfaces. The sections, when replaced, can also be recycled. But engineers will be watching to see how the track stands up to wear and tear and if the hollow structure causes resonance, which would make such a road unduly noisy.
Read the full story at https://www.economist.com/science-and-technology/2018/09/15/road-makers-turn-to-recycled-plastic-for-tougher-surfaces.