Making durable roads with waste plastic

The Philippines generates around 2.7 million tonnes of plastic waste per year, and is the third largest contributor to ocean plastic waste globally. While PET has economic value which incentivises recycling, polyethylene (used in shopping bags and shampoo bottles) and polypropylene (used in sachets and flexible packaging) do not. As a result, they are discarded after use and often land up in rivers and oceans.

Following successes in Thailand and Vietnam, Dow partnered with San Miguel to build ‘plastic roads’ incorporating post-consumer recycled plastic at a logistics centre in Cavite. The 1,500 square meter test site receives high traffic in the form of 18-wheelers and heavy equipment, and used around 900 kilos of post-consumer plastic as a binder together with bitumen to produce a strong and durable road surface. The plastic displaced around 8% of the bitumen (a petroleum-based hydrocarbon) that would normally have been used.

Every kilometre of plastic road uses over 2,500 kilos of plastic waste, and creates a ‘demand’ for these otherwise unwanted plastics. Using waste plastic instead of bitumen also reduces the cost of road construction. Studies indicate that plastic roads exceed the standards of the Department of Public Works and Highways and last longer than conventional roads, reducing the amount of materials required over the road’s lifespan. San Miguel has expressed interest in paving another 5,000 square meters of plastic roads.