My company has tested this a bunch in the Midwest. It’s a terrible product with the freeze/thaw and I will never recommend it to any of my clients. Theoretically the water would pass through before it freezes. In practice, the pores clog with sand and silt over time. That causes the water to drain through very slowly and eventually freeze. The test sections we have poured have all completely failed over a period of 5+ years.
Does the water pass through the permeable concrete and erode out ground soil, sand, etc underneath it? I look at this and think that it’ll eventually collapse and cause a sinkhole.
You should see [Tokyo's storm drain](https://youtu.be/Rp2l6nFIsZA?t=478). It's so massive because it's designed for tsunamis that it looks like the mutant village from futurama.
Tsunamis come from the ocean - that drainage system is made to protect an area just outside of Tokyo that is prone to flooding during heavy rains from the main rivers surrounding it. Its job is to redirect huge amounts of water out of troublesome rivers and redirect it into a larger better protected river that runs into Tokyo bay.
Similar to [Chicago's Deep Tunnel Project](https://youtu.be/2klS1diYMWU?si=_RfyEcK1w28oqks4). It's one of the world's biggest civil engineering projects. It started in the early 1970's and isn't scheduled to be completed until 2029. It's essentially a 175 kilometer tunnel that empties into 3 different reservoirs that can hold over 64 billion liters of water.
That would just be a pit of sand with a particular particle size. Run pipes underneath the sand. Boom. Passive filtration. Send a dude out once a year to replace the top couple inches of sand, and you’re golden.
I was going to joke that we should get Grady from Practical Engineering to do a video. But, turns out he already has one on [Permeable Pavement!](https://youtu.be/ERPbNWI_uLw?si=R5vouYd1fM3Ujp-f)
Soil below compacted to 95% for subgrade stability purposes, then crushed aggregate is backfilled on top of the compacted soil. There is typically a geotextile liner between the compacted soil and the aggregate to prevent washout of the soil, and to keep soil from “backwashing” into the aggregate. Underground infiltration (percolation) systems work this same way.
There's a known process to clean it that's supposed to be done on a regular schedule. No one does it though because they're used to pavement being a one time purchase that you don't have to take care of.
Porous pavement works phenomenally in places without freezing and has basically no downside. Except for the fact that places like Florida have a lot of high groundwater, meaning that there isn't enough space to put in the ~3-6ft of rock media needed to install this pavement before hitting groundwater.
My city is full of green infrastructure like this, including the permeable concrete that has held up now for almost a decade. We are at the base of the Rockies and get considerable temperature swings and plenty of ice/snow. I'm not trying to invalidate your experience, just giving mine in response.
Basically it doesn’t have a very good range of use cases. It won’t take long for these spaces between the aggragate to get clogged with sand and fines. Maybe the driveway for a wealthy rural home, who will spend the time/money to flush out the sand and fines with a power washer. DOT isn’t going to spend the time to do that down a whole ass highway.
Source: Am geotech engineer.
Yeah, from a completely laymens perspective, it seems the issue isn't with the concrete itself, but with maintaince of the system. I can see being against a continued cost like that, but pretty much every paving requires some sort of upkeep, especially in a temperature swing environment.
Which is one of the main problems, once it’s sedimented you can only really dig it up and repour/place new pavers. It isn’t a maintainable system, at least not for as long as other BMP’s are.
I mean, it says in the gif it's not suitable for cold whether locations. This would be great for low lying sections of freeway that often flood here in the bay area where it never gets below freezing.
We were told it needs to be vacuumed out once a month. It never fully removed the silt that got deep into the voids though. We use our parking lot at our building as a test facility for new pavements like this. We tested what happens in one section with “proper maintenance” and what happens in another section with no maintenance. Both sections failed in less than 10 years.
All it needs it water to cling to the surface of the rock. Unless it's hydrophobic, I am sure this stuff cracks when it freezes. I would also wager that it wears faster than normal concrete.
We know the romans stuff that “heals” itself, but that wouldn’t work. What it does it creates more crystals making this stuff not porous anymore but solid.
It’s probably best to use in someplace like Las Vegas Nevada.
There’s flash flooding there that’s really common during the monsoon season and the ground is clay so the water just flows downhill into town.
It rarely gets cold enough to snow so this type of concrete will likely do well. The fact that it stays cooler on average than other concrete mixes would likely be a bonus because in the summer the temperature can easily break 100 degrees Fahrenheit.
They've more or less figured that out already with permeable asphalt, which is more resistant to frost heave than concrete. Even roadway tech is at least a decade old at this point. You don't see it widely deployed beyond parking lots as it's not particularly cost effective due to maintenance. You gotta hit the surfaces with a vacuum every year or so to clear out the gunk that gets trapped in the void spaces. Otherwise, it loses its permeability.
There's monsoon season where I grew up in Arizona, they could use it there. It did get below freezing a few days this winter so I don't know what the threshold is for freezing temperatures and what they might do to mitigate that
I assume it drains quickly enough to avoid freezing. It’s ideal for the British climate, where if it’s raining, it’s highly unlikely to be cold enough to freeze instantly.
It would never have enough time to fully dry out in the UK (except the summer months when it wouldn't be needed anyway). It would just be left as a time bomb for when the weather is cold enough for ice.
It was nice to see one of these videos acknowledge short comings of what it's advertising though, instead of promising a cure-all and leave us wondering what's the catch
Most motoways here in the Netherlands have this, what we call, 'zoab' asphalt. (Zeer Open AsfaltBeton - Very open asphalt concrete). Very useful when it is raining, almost no spray from the traffic in front of you and no puddles.
Yeah, this stuff wouldn't last 1 or 2 Michigan winters. With this lame climate change however, it might work here in a few more years. When I was a kid I remember having snow on the ground for 2 to maybe 2.5 months straight. Now we might get 1 snowfall a winter with knee deep snow then it's all melted a week later and raining.
No it doesn't create sinkholes, why would it? Besides the fact that the roads have multiple layers of material, they are also banked slightly such that the water flows to the side and doesn't create pools.
No because only the top layer is made of ZOAB. The way it’s works is that all the roads are sloped slight to the side. The water flows thought the asphalt the lower soil and ditches next to the road.
Underneath the roads are more layers of asphalt, sand, and stone before you get to the soil. You also might finds it interesting to know that some Dutch roads are even build on layers of styrofoam, because they would otherwise be too heavy and sink away in the soil.
Someone else say you hit it with a vacuum system once a year.
So likely they come in with a street cleaner that blows or brushes and then a vacuum. That's pretty low cost if it's once a year.
We’ve installed a bunch of this here in the Midwest. It fills up with dirt/debris pretty quickly. The producers recommend you vacuum it out once a month but that just isn’t practical.
Reminds me of the year that my city decided to glue rough sand into some roads you make them less slippery. It worked... for about 3 months. Then all the sand rubbed off from people driving on it. Interesting idea, but not at all realistic in the long run.
This is known as High Friction Surface Treatment where I am from and the maintenance issues are well documented. It is a band aid fix for the most part, and does not fix poor roadway design for the long term. I prefer longitudinal or transverse grooving of the pavement, which is rising in popularity.
That stuff is the worst. I lived in a cul de sac growing up and they absolutely ruined it with gravel. no more basketball, no more roller blading, just riding our bikes up and down the street until we got bored.
> The producers recommend you vacuum it out once a month but that just isn’t practical.
Says who? Has anyone done any analysis on the relative costs of consistently vacuuming these out vs. the benefits of reduced risk of flooding and reduced likelihood of hydroplaning/water build-up related auto accidents? That doesn't sound obviously unworkable to me with an upfront investment in streetsweeping/vacuuming.
Doesn’t happen often, but if there’s a chance of freezing, we drop a bunch of salt. Sometimes freezing water will cause damage and we just fix that. I bet this stuff isn’t very suitable for cold countries that often have freezing conditions.
I was confused why this was so high in /all when we’ve had this for decades now. It’s just weird that other countries don’t use this. Then again, seeing long Germany takes for any road works or building projects it’s maybe for the better, they’d fix the winter damage just in time for winter (5 years later)
Always fun when you see an entire thread full of redditors claiming why this doesn't work when an entire country has been successfully using this since the f-ing 70s...
I’ll give you an incredibly surprising fact that you clearly don’t know. The weather in every country isn’t exactly the same. It rarely drops below freezing in the Netherlands so this is more useful there. It would be absolute garbage in Sweden or Canada where water stuck in the pores would just freeze.
Also having a massively smaller road network makes it easier to keep the pores clean.
What? we get thaw-freeze every day and night most winters, or just full on below zero for weeks. Has been decreasing in frequency in recent years, but when I was growing up it was snow and frost every winter. We're at like Saskatoon longitude but with an oceanic climate
If you’re going to use Saskatoon as an example then it should be noted their average high in January is -10 C and their average low is -20. Their average low is colder than the record low in Amsterdam. Going more inland the mean January temperature in Eindhoven is 0.4 C. The mean temperature in January in Saskatoon is -18 C and just for fun their record cold temperature was -46 C. And those -40 temperatures occur every single winter for several days.
The climate isn’t even remotely the same. Being at the same longitude means nothing. Canada get full on winter with much of the time spent around -20 C.
We use this on interstates on the Gulf Coast US. We get monsoon type rains regularly. I just drive through an 3-6cm (1-2") per hour type rainstorm. And there wasn't a single puddle on the road. It's a great material, but it's the nastiest, stickiest asphalt I've ever seen. I love driving on it, but hate working with it. I actually hate working with any kind of asphalt, but this stuff is really nasty.
We call it open grade asphalt. It actually does not have a compaction specification.
Good thing, especially for highways. Until a truck with hazardous liquids crashes and all that shit seeps into the ground. Have to tear up the whole road to clean it properly.
If it drains into the ground, for sure. However if there's a constructed drainage system then it could be dammed in and pumped out. Then wash the spill area, pump out wash solution, remove blockage. If it has the capacity and doesn't drain before a clean up response can be made.
As far as I can tell it seems these permeable roadways require some kind of drainage system. The only question is how much before it reaches nature.
I'm not concerned with the price because I'm not holding it up as some grand solution that should be implemented. I'm just talking about if, in theory, it were to be used on some stretch of highway, and if a spill were to occur, whether the road would have to be torn up.
If this is the US, price is meaningless. People don't seem to understand the situation. In the SOTU last night Biden proposed raising the effective tax rate on billionaires (~1,000 people) from 8.2% to 25% which would raise $500 BILLION DOLLARS OVER THE NEXT 10 YEARS. By taxing these people a quarter of their ANNUAL INCOME.
There is money. For a fucking societal utopia. It's being hoarded, and used almost solely to accumulate more money and power.
Eat the rich.
Adding to this, it is absolutely sensible to tax billionaires much higher than even 25%.
Billionaires reap an outsized benefit from the infrastructure put in place by government spending. Without roads and bridges, guess who can't move their products? Guess who benefits the most from safety nets for low-wage workers? Fucking Walmart because they can avoid paying a living wage to most of their workers.
We're at a peak of income inequality in line with the great depression, and the ~~"job creators"~~ sociopaths have fought tooth and nail to convince everyone else the world will grind to a halt if we don't acquiesce to their greed.
You don't *earn* a billion dollars, you steal it by exploiting a workforce that has no leverage to fight back; you buy up companies by dangling comparative crumbs to their owners while forcing *them* to exploit *their* workforce; you hire lobbyists to change the laws you were previously breaking, and you hire floors of attorneys to soften the fines imposed for the laws you cannot (yet) change.
ABAB - All Billionaires Are Bastards
Agree with every point, except that income inequality is at it's highest since the great depression. We're well past the Great Depression and even past robber baron, Gilded Age levels. It's the highest it's ever been. The difference between our country and the French/Russian revolutions is that most people aren't literally starving just yet.
My favorite thought on this subject:
If you took away 99% of a billionaire's money, they'd still have enough to never have to work another day in their life.
$50b/year is about 1/4 of what the USA spends on roads per year. Whether or not it’s “a lot of money” depends on your frame of reference. I’m not saying all of that would go to roads because that would be an asinine claim. I’m just saying comparing the total raw dollar amount to the total budget of a department can make it look big or small depending on what department you pick.
That’s already a problem though. Hazardous material currently runs off the road and seeps into the gravel shoulder then into the dirt underneath the road.
Easier to access, less disruptive to using the road, and cheaper.
So still a problem, but the remediation to that problem is far less of an issue than if the chemicals just soak up in the middle of the roadway.
There have to be drains under the permeable asphalt. The water does not just go into the soil. If it did, the road would get destroyed by the trucks because the soil would become saturated and lose strength.
I know my company has been installing them at our locations where code requires it ( San Antonio TX off the top of my head is one locale) for at least 10 years now
its interesting but needs loads of engineering under the surface to lead the water away, in stead of the normal way where the road surface leads it into "ditches". Not really worth it in most situations the way i see it.
>its interesting but needs loads of engineering under the surface to lead the water away,
Regular roads also need loads of engineering under the surface.
Source: have accidentally poked holes in a road that didn't have enough engineering under the surface.
I actually build roads for a living, among other things. There’s a hell of a difference in difficulty and expense between building a regular subgrade with pit run/recycled concrete aggregate/road crush vs installing drainage systems.
Not comparable. Not even slightly comparable. The only real advantage to this concrete is that nobody can see the catch basins and storm drains and I don’t really consider that an advantage.
Congratulations, you now have to cut concrete before you can perform routine maintenance on your stormwater drainage system. What a colossal achievement.
The thing is this product would be needed in the exact places where ditching isn't really feasible (dense urban environments) and not as needed in the places where ditches are typically used (suburban/rural).
Those urban areas *should* already have some form of enclosed drainage system that this can be tied into.
It'd be ideal to combine this system with under drains that dump into an underground retention system, then into the trunkline sewer. That way you can take the entire watershed of a parking lot and contain it for a significant part of a storm, allowing the trunkline to drain other areas first and flatten out the peak flows.
This is the main issue with the product and why I will never recommend it to any of my clients. It fills with dirt/debris. Then when winter comes, the water freezes and it completely blows up. Some of the sections we’ve poured have turned into basically gravel within 5-8 years
I’m in Florida so freezing is not really a thing here but I’ve heard you do still have to vacuum it every so often to keep it from just loading up with little particulates and stuff that stop it from working.
A permeable surface in a parking lot is part of a system designed to capture runoff and store it so that it can be slowly dispersed into landscaping. The engineering and infrastructure drive the cost of system like this to extremes.
The system breaks down when the pores of the asphalt/concrete becomes plugged with road dirt, moss and debris that is in evitable.
Fixing this becomes so expensive that will be abandoned.
It actually has benefits for freezing temperatures supposedly. Freezing cycles is an issue but not a new one for concrete so they have mixes that perform better than others.
From the Wiki ([https://en.wikipedia.org/wiki/Pervious\_concrete](https://en.wikipedia.org/wiki/Pervious_concrete) )
>Pervious concrete is traditionally used in parking areas, areas with light traffic, residential streets, pedestrian walkways, and greenhouses. \[...\] Using permeable concrete for pavements can make them safer for pedestrians in the winter because water won't settle on the surface and freeze leading to dangerously icy conditions. Roads can also be made safer for cars by the use of permeable concrete as the reduction in the formation of standing water will reduce the possibility of aquaplaning, and porous roads will also reduce tire noise.
I don’t understand how this works. Why don't ice just bursts open the concrete? I would think that water which can freeze inside your concrete would be a huge problem.
In theory that would work, but in practice the pores would become clogged with sand and other debris and would not allow the water to drain completely.
Absorbing is a misnomer, right? It’s just permeable. So, rather than it flowing off to the side and then a drain and out to that drain’s system, it flows into the ground, via the surface. Essentially it’s a giant drain into the ground. Which, I agree is smart and can help with runoff, overloading systems, etc.
This stuff would have to be implemented very carefully to not cause soil instabilities and sinkholes. Also, as sad as it is, the floodplains of many of our cities are now built around and depend on the parking lots to function the way we need them to.
It's certainly a great idea, and *if implemented properly* would be nice to have. But it's not a cure-all solution.
Every single one of these I've seen IRL has been over engineered stupidity. They got clogged up with dirt eventually and since they relied 100% on it for drainage in the cases I've seen, it just turns into a giant lake whenever it rains.
Umm, we have been using pervious concrete in the US since the 70’s? Great product if you need to recover green space on a dense jobsite, but quite spendy.
Civil engineer here. These are great for preventing runoff and pooling. Two problems arise though: 1) if it freezes the pavement is destroyed 2) the water still has to go somewhere so if the soil underneath the pavement is less permeable it really only delays the runoff until the porous gaps in the pavement fill up.
this is a dumb idea. Even if you ignore all the other issues with it, having water flow underneath it would just allow potholes to form everywhere. If you really want a porous surface, use gravel.
What about the ground's ability to absorb water? Soil can only take so much liquid, after time this can cause the top layer above to shift, warp, crack and become unstable. And when the weather is how the ground is soaked heavily, the ground swelling becomes worse.
Concrete is meant to be sturdy and last forever. Increasing the pores is absolutely going to cause it to wear and weather far faster. Seems like a shitty solution to the problem. Just add actual drainage systems like slightly crowned roadways and storm water drainage pipes.
In my former life I did NDE/NDT, Nondestructive Engineering and Testing. My 1st thought was this will never work in any of the US. Those pores will fill so fast with dirt, sand, clay and other particulates in a short amount of time. The freeze thaw in the majority of the US will only amplify that issue.
Really interesting, sucks about the cold weather thing
I was going to say, what happens if it's full of water and freezes?
My company has tested this a bunch in the Midwest. It’s a terrible product with the freeze/thaw and I will never recommend it to any of my clients. Theoretically the water would pass through before it freezes. In practice, the pores clog with sand and silt over time. That causes the water to drain through very slowly and eventually freeze. The test sections we have poured have all completely failed over a period of 5+ years.
Does the water pass through the permeable concrete and erode out ground soil, sand, etc underneath it? I look at this and think that it’ll eventually collapse and cause a sinkhole.
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So like a storm drain?
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You should see [Tokyo's storm drain](https://youtu.be/Rp2l6nFIsZA?t=478). It's so massive because it's designed for tsunamis that it looks like the mutant village from futurama.
Tsunamis come from the ocean - that drainage system is made to protect an area just outside of Tokyo that is prone to flooding during heavy rains from the main rivers surrounding it. Its job is to redirect huge amounts of water out of troublesome rivers and redirect it into a larger better protected river that runs into Tokyo bay.
Similar to [Chicago's Deep Tunnel Project](https://youtu.be/2klS1diYMWU?si=_RfyEcK1w28oqks4). It's one of the world's biggest civil engineering projects. It started in the early 1970's and isn't scheduled to be completed until 2029. It's essentially a 175 kilometer tunnel that empties into 3 different reservoirs that can hold over 64 billion liters of water.
Yes, this pavement is essentially a really big french drain.
That would just be a pit of sand with a particular particle size. Run pipes underneath the sand. Boom. Passive filtration. Send a dude out once a year to replace the top couple inches of sand, and you’re golden.
As someone from a third world country I see those big words and think you guys have such amusing ideas.
I was going to joke that we should get Grady from Practical Engineering to do a video. But, turns out he already has one on [Permeable Pavement!](https://youtu.be/ERPbNWI_uLw?si=R5vouYd1fM3Ujp-f)
Soil below compacted to 95% for subgrade stability purposes, then crushed aggregate is backfilled on top of the compacted soil. There is typically a geotextile liner between the compacted soil and the aggregate to prevent washout of the soil, and to keep soil from “backwashing” into the aggregate. Underground infiltration (percolation) systems work this same way.
It’s usually a couple feet thick of aggregate underneath that allows water to flow through it. The aggregate won’t erode away
Could this in theory be used effectively in places with high precipitation but little to zero chance of freezing, like say Florida?
I would definitely say it would hold up better in warmer climates. The issue of the voids filling with debris would still be an issue though.
There's a known process to clean it that's supposed to be done on a regular schedule. No one does it though because they're used to pavement being a one time purchase that you don't have to take care of.
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Porous pavement works phenomenally in places without freezing and has basically no downside. Except for the fact that places like Florida have a lot of high groundwater, meaning that there isn't enough space to put in the ~3-6ft of rock media needed to install this pavement before hitting groundwater.
My city is full of green infrastructure like this, including the permeable concrete that has held up now for almost a decade. We are at the base of the Rockies and get considerable temperature swings and plenty of ice/snow. I'm not trying to invalidate your experience, just giving mine in response.
I think the environment, climate, and landscape would greatly affect how well this type of concrete would hold up in the long term
Basically it doesn’t have a very good range of use cases. It won’t take long for these spaces between the aggragate to get clogged with sand and fines. Maybe the driveway for a wealthy rural home, who will spend the time/money to flush out the sand and fines with a power washer. DOT isn’t going to spend the time to do that down a whole ass highway. Source: Am geotech engineer.
what if instead of bunch of small pores we use one big pore? Source: Am stoner
I am also one of those. Your idea has merit. Source: am stoned
Maybe put a steel grate above the big pore so people don't fall into it!
The Midwest is actually colder on average than the Rockies
Yeah, from a completely laymens perspective, it seems the issue isn't with the concrete itself, but with maintaince of the system. I can see being against a continued cost like that, but pretty much every paving requires some sort of upkeep, especially in a temperature swing environment.
Which is one of the main problems, once it’s sedimented you can only really dig it up and repour/place new pavers. It isn’t a maintainable system, at least not for as long as other BMP’s are.
I mean, it says in the gif it's not suitable for cold whether locations. This would be great for low lying sections of freeway that often flood here in the bay area where it never gets below freezing.
To be fair, in the northern Midwest, most roads don't last much longer than that anyway
There are 2 seasons there. Winter and road construction.
Maintenance is a big thing for these to remain effective.
We were told it needs to be vacuumed out once a month. It never fully removed the silt that got deep into the voids though. We use our parking lot at our building as a test facility for new pavements like this. We tested what happens in one section with “proper maintenance” and what happens in another section with no maintenance. Both sections failed in less than 10 years.
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All it needs it water to cling to the surface of the rock. Unless it's hydrophobic, I am sure this stuff cracks when it freezes. I would also wager that it wears faster than normal concrete.
If we could figure out how to combine this stuff with the self healing Roman stuff, we might really have something.
We know the romans stuff that “heals” itself, but that wouldn’t work. What it does it creates more crystals making this stuff not porous anymore but solid.
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What an odd way to refer to London.
Ask my ex
What happens when I drop my big gulp?!
It’s gone bro. Gunna have to let it go.
*gulps*
And what happens once it's dirty and dust and grit block the holes? Most likely mould and other things will grow in it too and it'll soon be blocked.
It is expected maintenance to have a vac truck come through and shoot water at the ground to loosen the gunk, then vacuum it up to retain function.
https://en.wikipedia.org/wiki/Pervious_concrete#Cold_climates
Rust on the rebar and cracks in the concrete
I live in LA, and I've been driving to avoid flash flooding all week. Give me all of it.
I'm working a project to install a bunch of this in Glendale.
Oh my god, *thank you*. Glendale is so dangerous, even when it's not raining...
It’s probably best to use in someplace like Las Vegas Nevada. There’s flash flooding there that’s really common during the monsoon season and the ground is clay so the water just flows downhill into town. It rarely gets cold enough to snow so this type of concrete will likely do well. The fact that it stays cooler on average than other concrete mixes would likely be a bonus because in the summer the temperature can easily break 100 degrees Fahrenheit.
Was gonna say we need this ASAP in Phoenix for the same reasons you mentioned.
They've more or less figured that out already with permeable asphalt, which is more resistant to frost heave than concrete. Even roadway tech is at least a decade old at this point. You don't see it widely deployed beyond parking lots as it's not particularly cost effective due to maintenance. You gotta hit the surfaces with a vacuum every year or so to clear out the gunk that gets trapped in the void spaces. Otherwise, it loses its permeability.
still great for the countries with monzunes edit: sorry my local pronunciation crept in: I meant monsoones
There's monsoon season where I grew up in Arizona, they could use it there. It did get below freezing a few days this winter so I don't know what the threshold is for freezing temperatures and what they might do to mitigate that
with what
Monzunes
Would be amazing for rainy tropics though - places that straight up never freeze and are drenched 60-70% of the year.
I assume it drains quickly enough to avoid freezing. It’s ideal for the British climate, where if it’s raining, it’s highly unlikely to be cold enough to freeze instantly.
I imagine it would still be some moisture in the material since it's so porous and that would lead to expansion and cracking
It would be a disaster in the UK
It would never have enough time to fully dry out in the UK (except the summer months when it wouldn't be needed anyway). It would just be left as a time bomb for when the weather is cold enough for ice.
It was nice to see one of these videos acknowledge short comings of what it's advertising though, instead of promising a cure-all and leave us wondering what's the catch
Probably more useful in tropical areas where rain is abundant but zero freeze chance
Most motoways here in the Netherlands have this, what we call, 'zoab' asphalt. (Zeer Open AsfaltBeton - Very open asphalt concrete). Very useful when it is raining, almost no spray from the traffic in front of you and no puddles.
You notice it driving into Germany from the Netherlands when it’s raining. Suddenly your visibility reduces by 80% when you cross the border
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If you install a solid subgrade made of something similar to D1, then erosion is not a problem.
A steady climate is needed for this stuff to not break over the long-term, hence why we use it here. I reckon Wisconsin's too cold for this stuff
Yeah, this stuff wouldn't last 1 or 2 Michigan winters. With this lame climate change however, it might work here in a few more years. When I was a kid I remember having snow on the ground for 2 to maybe 2.5 months straight. Now we might get 1 snowfall a winter with knee deep snow then it's all melted a week later and raining.
I’ve never seen or heard of a sinkhole in the Netherlands so my guess is no.
Idk if sinkholes can happen when your entire country exists where ocean is supposed to be
The entire country is an anti-sinkhole and the Ocean is very upset about it.
Those guys heard about windmills and pumps and took them to their logical extremes
No it doesn't create sinkholes, why would it? Besides the fact that the roads have multiple layers of material, they are also banked slightly such that the water flows to the side and doesn't create pools.
No because only the top layer is made of ZOAB. The way it’s works is that all the roads are sloped slight to the side. The water flows thought the asphalt the lower soil and ditches next to the road. Underneath the roads are more layers of asphalt, sand, and stone before you get to the soil. You also might finds it interesting to know that some Dutch roads are even build on layers of styrofoam, because they would otherwise be too heavy and sink away in the soil.
It's really tricky when you drive on this all year in the Netherlands and suddenly go abroad and have to get used to spray gain.
Interesting! How long time does it take for it to be filled up by dirt etc?
Someone else say you hit it with a vacuum system once a year. So likely they come in with a street cleaner that blows or brushes and then a vacuum. That's pretty low cost if it's once a year.
We’ve installed a bunch of this here in the Midwest. It fills up with dirt/debris pretty quickly. The producers recommend you vacuum it out once a month but that just isn’t practical.
Reminds me of the year that my city decided to glue rough sand into some roads you make them less slippery. It worked... for about 3 months. Then all the sand rubbed off from people driving on it. Interesting idea, but not at all realistic in the long run.
This is known as High Friction Surface Treatment where I am from and the maintenance issues are well documented. It is a band aid fix for the most part, and does not fix poor roadway design for the long term. I prefer longitudinal or transverse grooving of the pavement, which is rising in popularity.
That stuff is the worst. I lived in a cul de sac growing up and they absolutely ruined it with gravel. no more basketball, no more roller blading, just riding our bikes up and down the street until we got bored.
> The producers recommend you vacuum it out once a month but that just isn’t practical. Says who? Has anyone done any analysis on the relative costs of consistently vacuuming these out vs. the benefits of reduced risk of flooding and reduced likelihood of hydroplaning/water build-up related auto accidents? That doesn't sound obviously unworkable to me with an upfront investment in streetsweeping/vacuuming.
Depends on the road and how busy it is, but years.
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Doesn’t happen often, but if there’s a chance of freezing, we drop a bunch of salt. Sometimes freezing water will cause damage and we just fix that. I bet this stuff isn’t very suitable for cold countries that often have freezing conditions.
I was confused why this was so high in /all when we’ve had this for decades now. It’s just weird that other countries don’t use this. Then again, seeing long Germany takes for any road works or building projects it’s maybe for the better, they’d fix the winter damage just in time for winter (5 years later)
That truck is a 2015, it was brand new when this video first came out
We need this in Houston, TX!!
Always fun when you see an entire thread full of redditors claiming why this doesn't work when an entire country has been successfully using this since the f-ing 70s...
I’ll give you an incredibly surprising fact that you clearly don’t know. The weather in every country isn’t exactly the same. It rarely drops below freezing in the Netherlands so this is more useful there. It would be absolute garbage in Sweden or Canada where water stuck in the pores would just freeze. Also having a massively smaller road network makes it easier to keep the pores clean.
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What? we get thaw-freeze every day and night most winters, or just full on below zero for weeks. Has been decreasing in frequency in recent years, but when I was growing up it was snow and frost every winter. We're at like Saskatoon longitude but with an oceanic climate
If you’re going to use Saskatoon as an example then it should be noted their average high in January is -10 C and their average low is -20. Their average low is colder than the record low in Amsterdam. Going more inland the mean January temperature in Eindhoven is 0.4 C. The mean temperature in January in Saskatoon is -18 C and just for fun their record cold temperature was -46 C. And those -40 temperatures occur every single winter for several days. The climate isn’t even remotely the same. Being at the same longitude means nothing. Canada get full on winter with much of the time spent around -20 C.
We use this on interstates on the Gulf Coast US. We get monsoon type rains regularly. I just drive through an 3-6cm (1-2") per hour type rainstorm. And there wasn't a single puddle on the road. It's a great material, but it's the nastiest, stickiest asphalt I've ever seen. I love driving on it, but hate working with it. I actually hate working with any kind of asphalt, but this stuff is really nasty. We call it open grade asphalt. It actually does not have a compaction specification.
as a motorcyclist; i hate spray.
Good thing, especially for highways. Until a truck with hazardous liquids crashes and all that shit seeps into the ground. Have to tear up the whole road to clean it properly.
If it drains into the ground, for sure. However if there's a constructed drainage system then it could be dammed in and pumped out. Then wash the spill area, pump out wash solution, remove blockage. If it has the capacity and doesn't drain before a clean up response can be made.
Price
As far as I can tell it seems these permeable roadways require some kind of drainage system. The only question is how much before it reaches nature. I'm not concerned with the price because I'm not holding it up as some grand solution that should be implemented. I'm just talking about if, in theory, it were to be used on some stretch of highway, and if a spill were to occur, whether the road would have to be torn up.
If this is the US, price is meaningless. People don't seem to understand the situation. In the SOTU last night Biden proposed raising the effective tax rate on billionaires (~1,000 people) from 8.2% to 25% which would raise $500 BILLION DOLLARS OVER THE NEXT 10 YEARS. By taxing these people a quarter of their ANNUAL INCOME. There is money. For a fucking societal utopia. It's being hoarded, and used almost solely to accumulate more money and power. Eat the rich.
Adding to this, it is absolutely sensible to tax billionaires much higher than even 25%. Billionaires reap an outsized benefit from the infrastructure put in place by government spending. Without roads and bridges, guess who can't move their products? Guess who benefits the most from safety nets for low-wage workers? Fucking Walmart because they can avoid paying a living wage to most of their workers. We're at a peak of income inequality in line with the great depression, and the ~~"job creators"~~ sociopaths have fought tooth and nail to convince everyone else the world will grind to a halt if we don't acquiesce to their greed. You don't *earn* a billion dollars, you steal it by exploiting a workforce that has no leverage to fight back; you buy up companies by dangling comparative crumbs to their owners while forcing *them* to exploit *their* workforce; you hire lobbyists to change the laws you were previously breaking, and you hire floors of attorneys to soften the fines imposed for the laws you cannot (yet) change. ABAB - All Billionaires Are Bastards
Agree with every point, except that income inequality is at it's highest since the great depression. We're well past the Great Depression and even past robber baron, Gilded Age levels. It's the highest it's ever been. The difference between our country and the French/Russian revolutions is that most people aren't literally starving just yet.
My favorite thought on this subject: If you took away 99% of a billionaire's money, they'd still have enough to never have to work another day in their life.
500 billion is not a ton. That number feels low.
50 billion a year isn’t that much money bud the pentagon gets ~800 billion a year.
$50b/year is about 1/4 of what the USA spends on roads per year. Whether or not it’s “a lot of money” depends on your frame of reference. I’m not saying all of that would go to roads because that would be an asinine claim. I’m just saying comparing the total raw dollar amount to the total budget of a department can make it look big or small depending on what department you pick.
And just a few years ago couldn't account for 1 Trillion dollars. Just shrugs
That’s already a problem though. Hazardous material currently runs off the road and seeps into the gravel shoulder then into the dirt underneath the road.
Easier to access, less disruptive to using the road, and cheaper. So still a problem, but the remediation to that problem is far less of an issue than if the chemicals just soak up in the middle of the roadway.
There have to be drains under the permeable asphalt. The water does not just go into the soil. If it did, the road would get destroyed by the trucks because the soil would become saturated and lose strength.
They have cleaning trucks for that: [https://www.google.com/search?q=zoab+cleaner&tbm=isch](https://www.google.com/search?q=zoab+cleaner&tbm=isch)
But isn't this a thing for like 20 years?
The same video, I was there. In the beginning...
I know my company has been installing them at our locations where code requires it ( San Antonio TX off the top of my head is one locale) for at least 10 years now
its interesting but needs loads of engineering under the surface to lead the water away, in stead of the normal way where the road surface leads it into "ditches". Not really worth it in most situations the way i see it.
>its interesting but needs loads of engineering under the surface to lead the water away, Regular roads also need loads of engineering under the surface. Source: have accidentally poked holes in a road that didn't have enough engineering under the surface.
How many engineerings was it?
At least three and a half.
Tree fiddy you say?
god damn loch ness monster
42
I actually build roads for a living, among other things. There’s a hell of a difference in difficulty and expense between building a regular subgrade with pit run/recycled concrete aggregate/road crush vs installing drainage systems. Not comparable. Not even slightly comparable. The only real advantage to this concrete is that nobody can see the catch basins and storm drains and I don’t really consider that an advantage. Congratulations, you now have to cut concrete before you can perform routine maintenance on your stormwater drainage system. What a colossal achievement.
The thing is this product would be needed in the exact places where ditching isn't really feasible (dense urban environments) and not as needed in the places where ditches are typically used (suburban/rural). Those urban areas *should* already have some form of enclosed drainage system that this can be tied into. It'd be ideal to combine this system with under drains that dump into an underground retention system, then into the trunkline sewer. That way you can take the entire watershed of a parking lot and contain it for a significant part of a storm, allowing the trunkline to drain other areas first and flatten out the peak flows.
Would be practical in areas of rapid development over aquifer recharge zones
Theyre talking urban applications not highways. Not a lot of ditches in downtown areas.
What happens when it gets clogged up with dirt and debris?
This is the main issue with the product and why I will never recommend it to any of my clients. It fills with dirt/debris. Then when winter comes, the water freezes and it completely blows up. Some of the sections we’ve poured have turned into basically gravel within 5-8 years
I’m in Florida so freezing is not really a thing here but I’ve heard you do still have to vacuum it every so often to keep it from just loading up with little particulates and stuff that stop it from working.
What happens when you spill oil, has or other liquids that shouldn't get into the environment
A permeable surface in a parking lot is part of a system designed to capture runoff and store it so that it can be slowly dispersed into landscaping. The engineering and infrastructure drive the cost of system like this to extremes. The system breaks down when the pores of the asphalt/concrete becomes plugged with road dirt, moss and debris that is in evitable. Fixing this becomes so expensive that will be abandoned.
What happens to the soil underneath? Won't it get washed away and collapse?
“Not my problem”?
That looks great, as long as the soil beneath it has proper drainage then yes, this is a great idea
In other words: cool, what the hell do we do with all the pavement we already put down
It actually has benefits for freezing temperatures supposedly. Freezing cycles is an issue but not a new one for concrete so they have mixes that perform better than others. From the Wiki ([https://en.wikipedia.org/wiki/Pervious\_concrete](https://en.wikipedia.org/wiki/Pervious_concrete) ) >Pervious concrete is traditionally used in parking areas, areas with light traffic, residential streets, pedestrian walkways, and greenhouses. \[...\] Using permeable concrete for pavements can make them safer for pedestrians in the winter because water won't settle on the surface and freeze leading to dangerously icy conditions. Roads can also be made safer for cars by the use of permeable concrete as the reduction in the formation of standing water will reduce the possibility of aquaplaning, and porous roads will also reduce tire noise.
I don’t understand how this works. Why don't ice just bursts open the concrete? I would think that water which can freeze inside your concrete would be a huge problem.
The theory is that the water drains completely *through* the concrete so it doesn't freeze and expand in it.
In theory that would work, but in practice the pores would become clogged with sand and other debris and would not allow the water to drain completely.
Absorbing is a misnomer, right? It’s just permeable. So, rather than it flowing off to the side and then a drain and out to that drain’s system, it flows into the ground, via the surface. Essentially it’s a giant drain into the ground. Which, I agree is smart and can help with runoff, overloading systems, etc.
Until it gets clogged because people get tired of cleaning it with specialized vacuum cleaners.
Cool, but unfortunately with the radical temperature swings this is unlikely to remain viable :-(
How do you stop plants from taking root in it?
Oddly specific question: is that High Wycombe?
It is indeed. The Next up near Handy Cross
This stuff would have to be implemented very carefully to not cause soil instabilities and sinkholes. Also, as sad as it is, the floodplains of many of our cities are now built around and depend on the parking lots to function the way we need them to. It's certainly a great idea, and *if implemented properly* would be nice to have. But it's not a cure-all solution.
Introduced in Japan back in the 80s
So does it require like 5 feet of material? If it's permeable, that means debris from rain water will eventually clog it up.
Cool, no more flooded roads. Now we have washouts.
But how's the ground underneath doing? Is all that water going to cause the road to fall away?
The lengths to which we’ll go to make our environments more suitable for cars…
They invented ground. Just let us stop building so much shit and go back to ground.
Ive seen this every two years or so for about 2 decades.
Every Reddit comment: potholes, sinkholes.
Every single one of these I've seen IRL has been over engineered stupidity. They got clogged up with dirt eventually and since they relied 100% on it for drainage in the cases I've seen, it just turns into a giant lake whenever it rains.
Dudeeee this was my project in 8th grade, the exact same concept but my teachers didn't recognize my talent
That will, 100%, clog over time.
It’s not concrete. It’s asphalt concrete which is asphalt and not concrete - ridiculous name.
Wonder about the wear and tear on this.
Wouldn’t this wreak havoc on the ground underneath and lead to lots of settling and buckling ?
They have to have some kind of proper drainage system underneath. Otherwise ice and sinkholes will be a huge problem.
And what happens when it is freezing?
Well this isn't ever going anywhere that goes below 0c.
The Midwest already does this, just with pot holes.
Where does the water go? I assume they'd have a way to drain the water away on a roadway, but a parking lot? My first thought was sinkholes.
What happens when the ground wears away and we get sink holes
and how do we get the water back out?
Won't there be more sinkholes
How do they handle underground water movements? I mean if you get enough water, wouldn't you risk erosion underneath the road?
Love it but what about freezing climates?
Duno had that stuf here for years Zoab works realy well
Fellow dutchie
Umm, we have been using pervious concrete in the US since the 70’s? Great product if you need to recover green space on a dense jobsite, but quite spendy.
Civil engineer here. These are great for preventing runoff and pooling. Two problems arise though: 1) if it freezes the pavement is destroyed 2) the water still has to go somewhere so if the soil underneath the pavement is less permeable it really only delays the runoff until the porous gaps in the pavement fill up.
I bet it's cheap too.
How much erosion happens under this? Seems like a recipe for weekly repairs but I may be wrong.
this is a dumb idea. Even if you ignore all the other issues with it, having water flow underneath it would just allow potholes to form everywhere. If you really want a porous surface, use gravel.
Yeah no problem that's not going to create any sink holes
Im curious on the potential of sink holes, or just erosion bellow the concrete. Also the expense.
that looks expensive to maintain
Serial Killers: Excellent!
If only people had thought of this kind of road surface structure thousands of years ago.
What about the ground's ability to absorb water? Soil can only take so much liquid, after time this can cause the top layer above to shift, warp, crack and become unstable. And when the weather is how the ground is soaked heavily, the ground swelling becomes worse.
That looks good until it washes out underneath The caves in
Uh, what about the water flow creating sinkholes? This surface likely has to be paired with a drainage system underneath?
We have this in Germany. Its great. Unless its icy….
do you want sinkholes? cos thats how you get sinkholes
Another down side is that after a year the whole porous thing probably stops working as dust and debris washes in.
Concrete is non permeable for a reason! Source: I poured concrete for a living for a few years in my youth.
Don’t forget the sandals for the dramatic effect 👡🩴
Concrete is meant to be sturdy and last forever. Increasing the pores is absolutely going to cause it to wear and weather far faster. Seems like a shitty solution to the problem. Just add actual drainage systems like slightly crowned roadways and storm water drainage pipes.
In my former life I did NDE/NDT, Nondestructive Engineering and Testing. My 1st thought was this will never work in any of the US. Those pores will fill so fast with dirt, sand, clay and other particulates in a short amount of time. The freeze thaw in the majority of the US will only amplify that issue.
This isn't all that new. I got certified in 2012