A major chemical company is building roads made of recycled plastic. They've already stopped 220,000

[thackney]

A major chemical company is building roads made of recycled plastic. They've already stopped 220,000 pounds of waste from ending up in landfills.
https://www.businessinsider.com/dow-chemical-recycled-plastic-streets-2019-2

Plastic gets a bad rap for clogging up landfills, polluting our oceans, and leaking toxic chemicals, but there may be ways to mitigate its damage.

Beginning in 2017, one of the world's largest plastic producers, Dow Chemical, began building roads with recycled plastic as a way to reduce waste. Their combined efforts have saved 220,000 pounds of waste from ending up in landfills.

After piloting programs outside the US, Dow has finally brought the project closer to home: In February, the company constructed two private roads at its facility in Freeport, Texas — about an hour outside of Houston — using 1,700 pounds of recycled plastic, or the equivalent weight of 120,000 plastic grocery bags.

While the roads still contain asphalt, they offer a practical use for a product that might otherwise turn into litter. (Dow wouldn't disclose the ratio of asphalt to plastic in its formula.)...

[thackney]

Sustainability Case Study: Turning Plastic Waste into Roads
https://corporate.dow.com/en-us/science-and-sustainability/2025-goals/case-study-rethinking-waste

...In India, Dow worked with government officials and waste collectors in the cities of Bangalore and Pune to bring together the people and materials needed for 40 kilometers of roads – diverting 100 metric tons of waste from landfills. (That’s equivalent to 25 million flexible pouches!) Volunteers pick up the plastic waste, which is taken to local recyclers, who process the material. The material is then sent to local asphalt plants, where they are used to replace bitumen and added to the asphalt mixture, resulting in roads that last longer than traditional roads.

“This project shows the creative solutions we can come up with when we collaborate with partners to create a sustainable system to advance a circular economy,” said Bambang Candra, Asia Pacific commercial vice president for Packaging & Specialty Plastics. “It engages communities on a local level and provides a new value to plastic litter in those communities.”

In addition to the roads lasting longer, they also reduced estimated greenhouse gas emissions by 30 tons by replacing nearly 10 percent of bitumen that would be used in road asphalt....

[rustynail]

Recycling robs future generations of raw materials and artifacts.

[catfish1957]

A major chemical company is building roads made of recycled plastic. They've already stopped 220,000 pounds of waste from ending up in landfills.
https://www.businessinsider.com/dow-chemical-recycled-plastic-streets-2019-2

Plastic gets a bad rap for clogging up landfills, polluting our oceans, and leaking toxic chemicals, but there may be ways to mitigate its damage.

Beginning in 2017, one of the world's largest plastic producers, Dow Chemical, began building roads with recycled plastic as a way to reduce waste. Their combined efforts have saved 220,000 pounds of waste from ending up in landfills.

After piloting programs outside the US, Dow has finally brought the project closer to home: In February, the company constructed two private roads at its facility in Freeport, Texas — about an hour outside of Houston — using 1,700 pounds of recycled plastic, or the equivalent weight of 120,000 plastic grocery bags.

While the roads still contain asphalt, they offer a practical use for a product that might otherwise turn into litter. (Dow wouldn't disclose the ratio of asphalt to plastic in its formula.)...

Interesting.  Only problem (from my industry experience) is that polyethylene has varying amounts of anti-oxidants which impact the structual durability and degradation  (PE-cross linkages) of the pellets and subsequent products.  Asphalt , as in the case of some of my. uses has been an excellent road surface for decades.

Issue 2... Slip.  PE depending on the application has a often animal based grease that gives the polymer, especially film the abilty to seperate .  A good example many garbage bags can seperate easily while opening (high slip) vs. those at the grocery store which are difficult (low slip).   Seems spent resins with high slip might exude slickness (esp. in high temperatures) and cause unintentional slippery road conditons. 

Plastic garbage has been used for lawn furniture , fencing , and other garden items for decades.   Not sure road aggregrate is such a great choice though.

[thackney]

Interesting.  Only problem (from my industry experience) is that polyethylene has varying amounts of anti-oxidants which impact the structual durability and degradation  (PE-cross linkages) of the pellets and subsequent products.  Asphalt , as in the case of some of my. uses has been an excellent road surface for decades.

Issue 2... Slip.  PE depending on the application has a often animal based grease that gives the polymer, especially film the abilty to seperate .  A good example many garbage bags can seperate easily while opening (high slip) vs. those at the grocery store which are difficult (low slip).   Seems spent resins with high slip might exude slickness (esp. in high temperatures) and cause unintentional slippery road conditons. 

Plastic garbage has been used for lawn furniture , fencing , and other garden items for decades.   Not sure road aggregrate is such a great choice though.

I thought I read it was a reduction in the asphalt used, not the aggregate.

https://resource-recycling.com/plastics/2018/01/12/dow-joins-project-building-roads-recycled-ldpe/

...According to a Google translation of a government press release, the process involves shredding LDPE into pieces of 9.5 millimeters or less. Washing and drying is required to remove contaminants, including organic residue. The plastic is then stirred into hot aggregate for about 10 seconds, allowing it to melt and covers the aggregate surface. Finally, hot asphalt cement is stirred into it for 35 seconds. The resulting pavement is more resistant to deformation and fatigue-cracking than standard asphalt....

[catfish1957]

I thought I read it was a reduction in the asphalt used, not the aggregate.

https://resource-recycling.com/plastics/2018/01/12/dow-joins-project-building-roads-recycled-ldpe/

...According to a Google translation of a government press release, the process involves shredding LDPE into pieces of 9.5 millimeters or less. Washing and drying is required to remove contaminants, including organic residue.

Slip is injected into PE during the extrusion process, meaning it is entrained into the resin on an absolute basis.  Even shredding the plastic into <10mm pieces is not going to remove the contaminant.  Have you ever used recycled plastic yard equipment. fences, etc?  There is an inherent greasy texture to it that is unavoidable. 

[thackney]

Slip is injected into PE during the extrusion process, meaning it is entrained into the resin on an absolute basis.  Even shredding the plastic into <10mm pieces is not going to remove the contaminant.  Have you ever used recycled plastic yard equipment. fences, etc?  There is an inherent greasy texture to it that is unavoidable.

Sorry I did not mean to imply that was going to remove the slip.  I understand the slip is entrained.  I have some experience with slip and extrusion into film for plastic bags and the like.

[catfish1957]

I thought I read it was a reduction in the asphalt used, not the aggregate.

https://resource-recycling.com/plastics/2018/01/12/dow-joins-project-building-roads-recycled-ldpe/
. The resulting pavement is more resistant to deformation and fatigue-cracking than standard asphalt....

Plausibly unless the mfg PE was made without any antioxidants as an additive.  Some films, bottles etc.  I have seem things like very old sandwich bags basically crumble before my eyes.  Wonder how that is a helpful addtion to asphalt?

OTOH things like landfill liners and the like have enough AO and UV stablizers in the PE to avoid degradation to near forever.

[Bigun]

Sorry I did not mean to imply that was going to remove the slip.  I understand the slip is entrained.  I have some experience with slip and extrusion into film for plastic bags and the like.

If I may inject myself into this, I think what @thackney is getting at is that the slip won't make much difference IF enough aggregate remains in the mix.

@catfish1957

[Polly Ticks]

I'm not an engineer (although I did give birth to one) so I can't speak to the chemical properties and such.  All I want to know is whether or not it will  help reduce all the freaking pot holes??

[catfish1957]

If I may inject myself into this, I think what @thackney is getting at is that the slip won't make much difference IF enough aggregate remains in the mix.

@catfish1957

Quite possibly true, but it would not take much exuded slip, say during high temperatures (and preciptiatiation) to impact road traction. In its neat form i have found this crap to be almost the most slipperiest stuff on earth.  It is aptly called "slip"

DOW is a huge company, and I am guessing their engineers and lawyers have determined it not to be signifiant issue or liability.  We'll see.

[Bigun]

Quite possibly true, but it would not take much exuded slip, say during high temperatures (and preciptiatiation) to impact road traction. In its neat form i have found this crap to be almost the most slipperiest stuff on earth.  It is aptly called "slip"

DOW is a huge company, and I am guessing their engineers and lawyers have determined it not to be signifiant issue or liability.  We'll see.

Oh yeah!  I worked for them early in my career. There is a reason why this is being tried out in India first!

[thackney]

Quite possibly true, but it would not take much exuded slip, say during high temperatures (and preciptiatiation) to impact road traction. In its neat form i have found this crap to be almost the most slipperiest stuff on earth.  It is aptly called "slip"

DOW is a huge company, and I am guessing their engineers and lawyers have determined it not to be signifiant issue or liability.  We'll see.

One of those articles talked about the aggregate covered by the plastic which was covered in asphalt.  I know the top is going to wear through but it may limit the amount of slip that comes out.  Making the road slippery obviously is not going to be acceptable.  I may have to find the road.  Freeport isn't far away.
.

[catfish1957]

One of those articles talked about the aggregate covered by the plastic which was covered in asphalt.  I know the top is going to wear through but it may limit the amount of slip that comes out.  Making the road slippery obviously is not going to be acceptable.  I may have to find the road.  Freeport isn't far away.
.

Road base would make more sense.  But when you realize that this plastic has to be processed (shredded), it seems the economics of this material vs. earthen based road bed material would be questionable.  Gubmit geen subsidized?

[thackney]

Road base would make more sense.  But when you realize that this plastic has to be processed (shredded), it seems the economics of this material vs. earthen based road bed material would be questionable.  Gubmit geen subsidized?

Remember no cost for the material, you would get paid to take like a landfill.  The cost of separating junk and cleaning would make the cost.  If set up for continuous commercial, would it compete with asphalt without subsidy?  I dunno.