Our oceans are dying partly because of plastic waste, and I used to think that limiting plastic production as well as banning single use would be the more effective remedies particularly against marine plastics. But I have started to see things in a different light, especially after I attended a forum co-hosted by the World Bank and the Norwegian Embassy in Manila.
I give credit to one presentation, in particular, from a private sector representative who noted that the Philippines did not produce nearly as much plastic products as other countries, and yet it was among the top producers of plastic waste in our oceans. In a sense, the issue is not our production or use of plastic, but our inability to properly dispose of our plastic waste.
In this line, I believe our incumbent as well as incoming lawmakers should give this issue more consideration. We desperately need measures to ensure strict enforcement of existing solid waste management policies, and the will to take “politics” and “corruption” out of garbage collection and disposal.
As the World Bank had noted, “millions of tons of plastic enter the ocean each year, a significant volume of which comes from the Philippines.” It had also noted that there were “no official statistics” as to “the magnitude of plastic waste thrown on land and ending up in rivers, lakes, and the oceans,” but “what is known is that the amount of mismanaged plastic waste is continuously increasing, and this crisis requires urgent action.”
What I hope can be among the viable local solutions to proper disposal of plastic waste is their use in energy production, and in construction. At this point, please allow me to tackle primarily the latter, considering the ongoing construction boom in the country as well as long terms plans for improving public infrastructure.
One study, out of the University of Baghdad, by researchers Zainab Ismail and Enas A Al-Hashmi, used waste plastic in concrete mixture as aggregate replacement. After 86 experiments and 254 tests, the duo concluded that reusing waste plastic as a sand-substitution aggregate in concrete could reduce the cost of construction materials and address plastic waste problems.
Research at the University of Bath also concluded that plastic waste could be a viable partial replacement for sand in structural concrete. The study, done in partnership with Goa Engineering College in India, showed that plastic waste in place of sand in concrete could help in the reuse of plastic waste as well as address India’s national sand shortage.
A study by Ahmad Jassim of the University of Basrah, meantime, concluded that “plastic cement” could be produced from mixing high density polyethylene waste (used plastic bottles and food crates) and Portland cement. He also noted that this cement’s “density was decreased, ductility increased, and workability improved,” resulting in the production of “lightweight materials.”
All these point to the viability of repurposing plastic waste into something productive and useful. More important, it also points to at least one of the ways to keep plastic waste from ending up in our oceans. At the same time, this approach cuts down on the need to further exhaust natural resources like sand, river pebbles, and rocks for use as concrete aggregates for construction.
What I would like our policy makers to consider is something similar to the effort in India, where a government order in 2015 has since required all road developers in that country to use plastic waste for road construction. Plastic waste is mixed with bitumen, using a technology first credited to Professor Rajagopalan Vasudevan of Thiagarajar College of Engineering in Madurai.
Some literature indicate that plastic-bitumen composite roads actually have better wear resistance than standard asphalt concrete roads. Also, they do not absorb water, have better flexibility which results in less rutting and less need for repair. Road surfaces also remain smooth, are lower maintenance, and absorb sound better. Moreover, the addition of plastic in asphalt can reduce the viscosity of the mix, allowing for a lower working temperature.
Waste from plastic product packaging are sorted, cleaned, dried, and shredded. The shredded plastic is then mixed and melted at a high temperature. Hot bitumen is then added and mixed with the melted plastic. After mixing, the mixture is laid as one would with regular asphalt concrete when building roads.
In the Indian cities of Pune and Bengaluru, for instance, they already have about 40 kilometers of roads that were built with recycled plastics. About 100 metric tons of waste were repurposed for road construction, which were said to be equivalent to about 25 million plastic flexible pouches — waste that could have instead ended up in landfills and perhaps in our oceans.
“Plastic” roads have also been built in Jamshedpur in India, and Indonesia’s Bali, Surabaya, Bekasi, Makassar, Solo, and Tangerang. Last year, the Dutch company Volkerwessels built a bicycle path made of recycled plastic in Zwolle, in northeast Netherlands. And just last January, the UK Department of Transport announced a £1.6 million trial of a plastic road technology developed by Scottish reinforcement company MacRebur.
Locally, in March, San Miguel Corporation announced that it would partner with Dow Chemical to start looking into building roads out of recycled plastic waste. The aim is to produce an alternative to asphalt using plastic materials that are “hard-to-recycle.” Dow has reportedly worked with partners in India, Indonesia and Thailand to use plastic waste in roads.
Beyond this effort, which is mainly private sector led, I hope that policy makers will consider providing support and incentives for industries effectively repurposing plastic waste. Moreover, I hope they will seriously look into a national call or government order, by legislation or by executive fiat, to utilize plastic waste technologies particularly in road construction.
Marvin Tort is a former managing editor of BusinessWorld, and a former chairman of the Philippines Press Council