“We wanted to target these two kinds of plastic waste because neither has high economic value after use. PET (the kind of plastic that goes into soft drink bottles) is collected and sold so it eventually gets recycled or disposed of properly, but because used sando bags and candy wrappers have not commercial value, they end up landfills or find their way to the ocean through our storm drains or rivers,” says Steve Piczon, SMC’s government affairs and advocacy manager whose job it is to incubate ideas that can be scaled across businesses.
Working alongside him for this specific project is the general manager of Dow Philippines, Bobby Batungbacal. “Plastic waste is the sustainability issue of our time. Dow is working with partners around the world to build plastic roads using post-consumer recycled plastic. We’ve had great success in Thailand and Vietnam where we’ve already demonstrated that it is possible to divert plastic waste toward this unique and really useful application.”
Both Piczon and Batungbacal were encouraged by the tests run by independent labs and third-party providers. “Initial tests showed that asphalt made with plastic is stronger. All the parameters that we set—bitumen content, air voids, marshal stability, permeability, density—were met,” reports Batungbacal who consulted his colleagues across the Asia-Pacific.
“But the proof is in the real-world trial and usage of the plastic roads, so we wanted to be very deliberate about the process and make sure that we got it right,” Piczon adds.
The proposed plastic road mix was tested thrice on different dates and in different quantities to make sure that it met DPWH (Department of Public Works and Highways) standards. Testing was done at Par Geotechnical Testing Center, a DPWH-accredited facility. In the final run, the team focused solely on the use of polyethylene given that the available third-party provider could only heat the plastic at temperatures of 180 degrees centigrade. Polypropylene requires temperatures of 200 degrees centigrade or higher, but subsequent tests will focus on using PET and polypropylene as additives. Another challenge was finding machines that could shred the plastic to pieces smaller than three centimeters.
The General Trias test site is a staging and marshaling area for San Miguel Integrated Logistics' growing fleet of 18-wheeler trucks. "We thought we'd put the durability of the road to the ultimate test. We want to see how it will perform when haulers and lorries drive over it," says Steve.
The trial site is only 1,500 square meters, but already San Miguel Can Asia (also in General Trias) has expressed interest to pave another 5,000 square meters with plastic roads. For the first 1,500 square meters in San Miguel's logistics center, roughly 900 kilos of post-consumer plastic were used—the equivalent of 180,000 plastic bags.
“We’ve seen how plastic roads perform in Thailand. It looks just like an ordinary road surface, but every kilometer of plastic road uses over 2,500 kilos of plastic waste. This is the goal for the next run in the Philippines, to use even more post-consumer waste and many more different types of plastic," says Batungbacal.
Studies show that plastic roads last longer and perform better than conventional roads. "Adding plastic increases resistance and the road's anti-slip properties. And because you’re substituting up to 8% of bitumen with plastic that would otherwise just be thrown away or worst end up in our oceans it can be more cost-effective to produce,” he shares. “If you scale it up, you might be looking at additional savings.
“But more than that, we’re doing the world a lot of good. We’re demonstrating that it’s possible to divert plastic waste and come up with useful, innovative real-world applications.”
Much of the plastic shredded came from Dow and San Miguel employees themselves. Adds Batungbacal, "Our entire family got into it, setting aside whatever plastic we used at home. And by the end of the month, we laid it all out and saw just how much the average Filipino family consumes in terms of plastic. It's made us so much more conscious about the issue of plastic pollution."
If all goes well in subsequent trials, San Miguel and Dow Philippines hope to take the idea further and bring the technology to local government units and other companies to initially use the technology for parking lots, side streets and pavements.
Says Piczon, "The hardest hurdle hasn't been the technology, it’s been convincing people to give the idea a go and to encourage them to experiment with the technology. Many of our third-party suppliers were skeptical and selling the idea wasn’t as easy as we thought it would be. On the day of the paving itself, representatives from San Miguel's infrastructure and packaging units were present, eager to document the process and see how they might adopt the technology in their businesses.
San Miguel's management led by company president and COO Ramon S. Ang says that pending further testing on the General Trias pilot, SMC plans to build plastic roads in its facilities and use the technology in the group's major infrastructure projects.
“We're already looking at the time when we are going to have an entire length of plastic road in the majority of our towns and cities. The goal is to use local plastic waste to produce local roads,” Piczon says. “That day is going to come, and I’m glad San Miguel and Dow helped pave the way.”
