How Does Permeable Pavement Work?

[@PracticalEngineeringChannel]

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[@sonuyadav1182]

By solving one problem you're creating another problem of ground water level and nitrogen fixation . I will not say that its a great idea because its not sustainable .

[@sonuyadav1182]

Sorry i commented earlier , you have address that problem

[@miheedd]

Водопроницаемый бетон можно использовать только в теплом климате. Иначе вода разрушит всё покрытие при частых циклах заморозки и разморозки. В многих странах даже непроницаемое покрытие не выдерживает таких воздействий. Днем тепло, лёд растает, а ночью замерзает (увеличиваясь в объёме и разрушая покрытия).

[@rgbii2]

Definitely interested in videos on flooding and ways to handle runoff. I live along the Colorado, and heavy rains around the Austin area flow by my place, and when it's really bad, flows over my place!

[@bashisobsolete.pythonismyn6321]

i enjoyed this one. i like this subject matter. BTW, it is more correct to say MANMADE. that's an actual meaningful word. don't be that guy; say MANMADE.

[@jameslmorehead]

A few years back, I called around to the local concrete companies to price out delivery of permeable concrete for my driveway. None of them knew what it was. I literally had to give them the full recipe and wait for them to call me back a day or two later with a quote. One big cost increase between regular concrete and permeable concrete is the rock. See, the rock for permeable concrete needs to be washed of debris, and within the size range of 3/8" (9.5mm) to 1/2"(13mm). Regular concrete can take the dust and debris and can have a size range of 1/4" to 3/4". The large size range actually makes the concrete stronger.

[@gr8dvd]

”give recipe" Not surprising as ALL building trades (and suppliers) are notoriously un-innovative.

[@hunterschulte9225]

What was the $/ cubic yard? Would be nice to consider for LEED projects but usually budget is the limiting factor.

[@wijayatan7870]

well they are robot minded worker is like that.. not inovative n scared new things

[@justgonnagetbetter1037]

@@wijayatan7870 the robot workers that make, install and maintain the roads, sidewalks and parking lots that you like to drive and park your high horse on aren't afraid of your imagined fears. Maybe if you had made it to the end of the video you would have noticed that Grady said that this is new technology that's hard to implement. Which means 95% of your concrete suppliers will probably not have heard of, let alone taken the time to learn the recipe for a concrete mix that maybe gets used .01% of the time currently.

[@teemun3979]

@@justgonnagetbetter1037 Exactly, not to mention the average employee only cares about what their boss tells them to care about in regards to their job. What kind of geek of a construction worker is going to be low on the managerial totem pole, but still be the first one to know about a new technology in their business?

[@Antix619]

As an inspector, the State of California does not understand this. Just gives a blanket credit for the project if you use pervious concrete or detention/retention basins. No determination of if it's practical or engineered to make it practical. Can't tell you how many times I've seen 4-5" of porous/permeable concrete sitting directly on native clayey subgrade. I always ask the contractor and Owner " Why even bother with the permeable concrete?" Answer: Because the government paid for it.

[@grassgeese3916]

i wonder how u stay sane!!!!! Woww

[@Allan_aka_RocKITEman]

California -- what a concept...🙄

[@Nanomachines5on]

Sounds like California! You can’t make this stuff up.

[@alanleuthard2689]

I've engineered several zero sum BMPs at client request due to CA policies. I literally have to spend design time making sure the useless basin I'm adding doesn't make things worse. It's usually an interesting exercise when taken by itself, but very cringey as I'm signing the plans.

[@RCBlooming]

is it at least better than not having permeable concrete?

[@chriseggenberger]

When I used to work for a sewer company I had a job inspecting some manholes at companies parking for potential blockages. The parking lot ended up flooding 1-2 feet with cars in the lot. It turned out when the building was renovated for office space they had to include a second detention area, but were restricted by how much space they had. Come to find out the last manhole had a 6inch outlet pipe. The engineers made the parking lot the second detention pond!

[@gavinli1368]

I’m sorry what? Did I read that right? How in the world did a design like that get approved?

[@Lady-Lilith]

Some codes do allow ponding in parking lots to account for detention, but I think it's limited to 6-inches of standing water limited to a certain percentage of the lot and it cannot block ADA paths. I've only seen it done a couple times, and generally warehouses will use areas by loading docks where people never walk on the ground.

[@rkf053fitz]

@@gavinli1368 That's actually a common strategy. You'll notice a lot of parking lots are a bunch of small basins that act as extra storage. You can increase storage by using larger pipes too, with a smaller pipe at the end to restrict the outflow. You'd often design the lot grading with tipping points that would release excess water if the system gets overwhelmed.

[@jpaugh64]

Well, it's better to flood the parking lots than to overload the drains and sewers.... I guess.

[@drowningflamingo]

Grady, I love that you use the same music for every video. It’s so comforting and familiar. I’m so grateful that you’re in this world with the patience to see the marvel of civil engineering and I’m grateful that you have enough patience left over to teach what you know. Life is hard for so many reasons right now and I’m just so grateful for all these videos you’ve made; they make things a little easier and they remind me of the joy of curiosity and learning.

[@robertpierce1981]

I agree with the repetitive music. I like it.

[@russrags6274]

I was just thinking the same thing, the music is perfect always

[@roccobastone1441]

probably helps a lot with editing and avoiding copyrights too

[@Kio.O]

This very comment has ruined my whooole interest in his videos entirely lol

[@tylerc3576]

@@Kio.O ? Get a grip.

[@Aaron.Reichert]

As someone who lives in an area that turns into a frozen hellscape for a quarter of the year, I have always been skeptical. It doesn't help that it is usually some viral Facebook post that leaves out all the important stuff like what is below the pavement. Thanks for your explanation of what is going on.

[@JustJoshtheDad]

I'm an DOT inspector, and on a DOT job,we recently used a permeable asphalt pavement, (open graded bituminous base), as a base course for concrete pavement. The permeable material was placed on top of 8" of agg base, then 4 inches of permeable base. then 9 inches of dowel jointed concrete. the permeable base had edge drains running along it, which then drained into the storm sewers. this was used to help keep water from deteriorating the concrete from underneath. The area had a history of bad soil, and holding water. This is starting to become a regular thing in Oklahoma. Another major job in Tulsa recently used permeable concrete in roughly the same configuration. I think the thought is, the concrete pavement above it, helps prevent alot of the surface issues it has, and the pavement also distributes the loads on the permeable concrete, so it doesn't fracture. Long time watcher, and alot of your videos have to do with Jobs I inspect on a daily basis so it is pretty cool learning more, and just being able to appreciate the engineering. thanks for all your videos.

[@The_Original_Forrest_Trump]

Sounds expensive and prone to freeze/thaw damage?

[@LeahLuciB]

How well does it handle ice?

[@JustJoshtheDad]

@@LeahLuciB it tends to ice up a little sooner. Air voids make the pavement cool faster. Soo yeah more ice

[@h8GW]

@forresttrump.7910 Still, if the water can drain out, ice wouldn't form in the first place. Also, the cavities will be mostly air, so any ice that does from has room to expand.

[@bdbgh]

Steel gratings are starting to be replaced with concrete gratings (not permeable concrete) in my country, since it gets stolen every now and then for scrap metal. The issue is the hazard more than the cost for replacement of the grating. This permeable pavement seems helpful for reducing the amount area needed for holes to divert water to the storm drain.

[@toohoney8674]

What country do you live?

[@TheRogueRockhound]

@@toohoney8674 Imma say eastern europe

[@sergarlantyrell7847]

Imagine walking through a puddle where a steel grate is meant to be, only to fall right into the flooded hole because some unscrupulous person pinched it.

[@emilianozamora399]

@@TheRogueRockhound eh it sounds like something they'd do in an undeveloped south american country

[@TheRogueRockhound]

@@emilianozamora399 Good call

[@jonboy545]

They have started paving large sections of interstate here in North Carolina with this new asphalt that the water just soaks right through. The impact in safety while driving is mind boggling. WIpers can almost be turned off completely. You don't feel like you're going to die every time you get behind a semi and all the water they throw off. It is astounding the difference it makes.

[@IntrepidInfinity]

I wonder how they're dealing with structural weakness problem. Might be worth an investigation

[@Twiggy163]

@@IntrepidInfinity no need, the Netherlands have paved their motorways with ZOAB (Dutch abreviation for very open asphalt concrete) since 1995. The top layer is exactly as @jonboy545 describes, it also reduces road noise and deforms less. So theres no ruts in the road. Under the permiable top layer, there is an impermiable layer to make sure the rainwater runs off to the side and doesnt affect the foundations of the road. The downsides are: shorter lifespan for the top layer (about 10 years vs 15 to 20 for regular asphalt), more sensitive to freezing (due to water freezing up inside the open layer, it will crack much faster) and newly layed open asphalt privides less friction which results in a longer brake distance. This gets better over time.

[@frenchys_prospecting]

It also helps regenerate the water table in built space areas

[@LeahLuciB]

How do they deal with ice? I'd fear that the water would expand in the gaps and break the pavement up

[@stevenschnepp576]

@@LeahLuciB By driving more, so the vehicle exhaust emissions contribute to global warming and prevent the ice in the first place. Modern problems: modern solutions.

[@oldtimefarmboy617]

I live in a semiarid part of the country so heavy rains and the runoff that goes with it is not a big problem. A few years ago a business built a new location using permeable material in the parking lot. One of the first things they did was to build a huge cistern that was reinforced to hold a lot of weight above it. When they started on the parking lot they laid an impermeable layer where everything was sloped to the intake on the cistern then topped it with permeable concrete. Now when it rains the run off from the roof and sidewalks flows to the parking lot and then to the cistern. The cistern also has a pump so that they can use that captured water to irrigate their landscape. The landscape is xeriscaped with native plants that do not require a lot of water, so the water from a good rain can last a long time before they need to make use of city water.

[@natesmodelsdoodles5403]

nice.

[@angrydragonslayer]

I was actually thinking of this one, why would you put a stone reservoir under it rather than an impermeable layer that leads to collection drains?

[@cinnamoncat8950]

@@angrydragonslayer im no engineer gaming but i think it might be so that the water can go into the ground instead of into drains which just lead into already over encumbered streams

[@angrydragonslayer]

@@cinnamoncat8950 i forgot that part of the video.....

[@TheMrVengeance]

Wow, neat. Learned the term xeriscaping now. Cool concept.

[@Bundesligahoffefan]

Note: permeable asphalt is usually used whenever parts of the autobahn network in Germany are being upgraded. It’s NOT just used for parking lots, at least here in Germany. By the way, it’s awesome to drive 180(km/h) on permeable asphalt when it’s pouring rain

[@harmg937]

In the Netherlands nowadays all our highways are made from permeable asphalt. Mainly to prevent water splashing during rain.

[@hanzzel6086]

Must be nice, not living in a frozen hell scape for half the year. It lets stuff like this survive for more than a year.

[@iyt6407]

@@harmg937 Also because it reduces road noise with about 5 decibels.

[@simo007_d7]

Also here in Italy permeable asphalt is used in highways and other busy roads such as “national roads” that are often 2 or 3 lanes wide depending on the area. Also parking lots here are not as big as in America so they're usually made out of normal asphalt, or in some cases as shown in the video they're made with those concrete squares with grass in the middle so that they can flush water right into the ground

[@MrMysticphantom]

I love the fact that you not only covered the concept in detail, and its important variables/parameters, but you also made showed where its beneficial, and where it should be avoided for use and why. Usually its always just one or thr other

[@mongogoose]

In some parts of India, our local PWD keep deep holes in the middle of the roads to collect rain water to slowly replenish the groundwater. We call them pot-holes, and i think its ingenious. It also slows traffic thus increasing safety for pedestrians. Unfortunately, It has received a lot of backlash from vehicle owners and old people.

[@moogle68]

underrated comment😆😆

[@CrystalClean333]

😂😂😂

[@samuelalalade2075]

🤣🤣🤣🤣🤣

[@StefsEngineering]

Ah the good old ZOAB (as we call it in the Netherlands). Pretty much all highways and a part of the urban roads are made of it. In new urban area's all pavements and most of the roads are made permeable with signs not to dump sand or limitations on the weight of vehicles that enter an area. Oh ZOAB stands for "zeer open asfalt beton" or directly translated: "very open asphalt concrete" Addition: I looked into it a bit more and it seems that the Netherlands started to use ZOAB in 1995, the newest versions are way more durable and a lot quieter compared to the earlier versions and especially in comparison to normal asphalt or concrete (-6dB).

[@pietvanvliet1987]

Brady: Makes video about water management. Me, when realising the solution is something the Dutch are doing for decades: Quick! To the comment section to find other Dutchies! Has anybody yelled "gekoloniseerd" yet?

[@StefsEngineering]

I looked into it a bit more and it seems that the Netherlands started to use ZOAB in 1995, the newest versions are way more durable and a lot quieter compared to the earlier versions and especially in comparison to normal asphalt or concrete (-6dB).

[@StefsEngineering]

@@pietvanvliet1987 Well hi there :P

[@mukrifachri]

I think it's different though... They just put the water to flow within the surface layer. Benath the surface layer it's still the fairly impervious HRA / AC / SMA right ?

[@StefsEngineering]

@@mukrifachri Depends on the loads it sees. Right lane on a highway needs to be a lot tougher than a sidewalk. (obviously) the sidewalks and roads in front of my home do have the shown layering of sand, gravel with a topcoat of permeable asphalt or "clinker bricks" that are also very common on sidewalks and roads. en.wikipedia.org/wiki/Clinker_brick

[@intrepid_wandering]

Channels like this are worth their weight in gold. A true asset to humanity.

[@michaelesposito2629]

LOL he was trying so hard not to smile while saying that “pave parking lots” song lyric 😂

[@RyanRiopel]

Big Yellow Taxi by Counting Crows, in case anyone was wondering

[@bidaubadeadieu]

@@RyanRiopel no no no, it's by folk legend Joni Mitchell! Counting Crows just did a cover

[@RyanRiopel]

@@bidaubadeadieu thanks for the tip! I grew up listening to the crows version on the radio

[@Lady-Lilith]

That smirk on Grady's face had me cracking up.

[@Mrcaffinebean]

It’s so heard to say it and not sing it 😂

[@Orrinn123]

I love how Grady always looks like he's so excited to teach us something

[@iturnacupover4139]

You know the days gonna be good when practicle engineering uploads

[@dabonkus]

yoo this dude just turned a cup, future engineer right here!

[@chrisgoosebeck]

I'm curious what the affect of freezing and thawing cycles for colder climates has on these designs in addition to long term collection of organic material and the potential for reducing the efficiency of flow.

[@Hellsong89]

Was thinking of this too. I have couple of places that could use this kind of setup, but it needs to be long term solution with minimal maintenance or least be able to clean it. Maybe slaps or tiles that can be lifted and underside reservoir be flushed and fine material separated every decade or so in private house yard.. bit more often on commercial area.

[@BillyBob-fd5ht]

pretty sure ice would win or to keep it from freezing salt or organic beet juice

[@mehere8038]

yeh, the organic matter is what I can't figure out how it works with. Surely if the onlyl thing missing in the mix is sand, then over time sand & silt & dust is going to clog it up?

[@oldgrunt5806]

Worked for Public Works in a major city in Minnesota, they tried this with permeable concrete many years ago. Did not work as it got plugged up and in winter started to break up. Wound up replacing it with regular concrete @ 8 years later.

[@challenger3603]

The other thing is in the northern climates you have to use anywhere from 4-8 times the salt to keep the road open. As the water drains it will freeze and start to bubble crack the road. You have to drop a 600 application on this type of road to keep the water from freezing where normal roads are about 200s. An 800-1200 in a heavy storm where a 400 to 600 is normal on regular pavement. This road would be best in places where the ground never freezes and temps never drop below 35 degrees.

[@ryanmcgowan3061]

Porous paving clogs very rapidly, even with sweeping, and especially in areas prone to dust. A better alternative is to use normal paving with linear grates over a deep bed of compacted crushed gravel. The grates drain into a perforated pipe along the aggregate bed. At the far end, you can do another perforated pipe for an outflow of cleaned water. The storage volume is determined by the outflow elevation to the bottom of the aggregate bed, which should be completely flat. For larger volumes, you're going to add Stormtech chambers.

[@slitor]

Like a spread field for your septic or a drip irregation system? Cost and maintanace would be a huge issue though.

[@ryanmcgowan3061]

@@slitor There's a lifespan to it, but a well-designed system will last decades. Proper pretreatment, catch basins, cleanouts, and soil conditions will have a big effect on longevity.

[@kdm28]

Had that the clogging problem in NM. Rural area with agriculture land and dirt roads. DOT bought a vacuum sweeper for maintenance but it's difficult to keep up

[@SmallSpoonBrigade]

@@kdm28 The lesson there is that not every technology can effectively be used everywhere.

[@Alex-us2vw]

The retention “ponds” we have around here don’t discharge storm water back to the storm sewers. They are usually in green space and just hold the water to filter into the ground over time.

[@kenoliver8913]

That depends on climate (ie how much precipitation), topography, soil type and how much free land there is. As the video mentions storm water management systems vary hugely according to local conditions. How useful permeable pavement is varies according to these - in some it will be absolutely ideal, in others useless.

[@haroldwong9235]

"pave paradise to put up a parking lot" smooooooooth 😁

[@l0renzz0]

counting crows reference

[@RG-3PO]

Or Joni Mitchell , Big Yellow Taxi reference

[@sarikatimmi]

jack johnson

[@RaymondHng]

@@l0renzz0 kzbin.info/www/bejne/b2XFlYCJeMmqaJI

[@l0renzz0]

@@RaymondHng thanks, first thing I did was searching for Joni Mitchell from Robert G's comment. I never knew Counting Crows did a cover

[@sethyuikora2]

Moved into a house where the previous owner lined the back yard with bricks. The bricks form enough of a seal to collect water in certain places and even makes it into a ground-level room sometimes. My next major project is to remove all of the bricks to fix help with that issue, but I was thinking of using home-made porous concrete blocks (similar to the circular one in this video) as a method of displacing the water while maintaining an earthen look to the yard. Thanks for this explanation as I would have no irrigation or reservoir to get rid of the excess and would've ended up wasting a lot of time and resources on it. Though I'm sure it would've helped to some extent, the cost and time wouldn't warrant the result.

[@karawillis4767]

Did you do this project? If so what were your final plans and would you change anything about it?

[@Skull-in-the-house]

I wonder how many kids watch this channel and eventually become engineers? I would bet it's a lot, he makes it seem so fun and interesting :)

[@sweepingtime]

And the best kind of engineer, the civil engineer.

[@tacocat1714]

It’s a lot better than School’s teach it, they just throw a paper packet at you and say something like: “Here’s your packet it’s 15 pages, test tomorrow good luck!”

[@meneldal]

@@sweepingtime I wouldn't say it's the best, but there's definitely a lot of fun stuff in civil engineering. Also probably easier for people outside the field to understand because the scale is close to us. Most people see electronics as just magic they can't understand, but a bridge, everyone can picture it.

[@NimithChanceson]

Learning engineering is fun. Dealing with contractors is not

[@benbarker8154]

My son is studying engineering at Miami University at Oxford, Ohio as a direct result of this channel. We started watching these videos together when he was in high school. He made the decision to be an engineer in his junior year.

[@elementalcore3454]

This channel reignites my motivation to try for a pre-engineering major in college. I am currently a geology major, and I can pair that very well with engineering. Funnily enough, I decided to watch this because of my geologic knowledge; a permeable material for infrastructure is a game-changer for mitigation of dangerous geologic events associated with water (which is a _very, very large portion of geology_ ).

[@kdm28]

Go for it I'm s civil engineer and many PEs where I worked at the DOT has geology degrees

[@shannonlove4328]

I’m surprised that permeable pavement doesn’t clog rapidly. I grew up in West Texas were dust is omnipresent, so my intuition is that any small pore material would be quickly infiltrated and blocked. How does this material’s porosity age? I would assume that under real world circumstances it would grow progressively less porous and eventually seal shut. What prevents that?

[@StefsEngineering]

In the Netherlands (mild climate quite wet but nothing too crazy) it has a lifespan around 11 years. The new stuff obviously works a lot better but it is allright after 10 years.

[@TomServo3006]

As a civil engineer in the NE, we avoid it for this very reason. Salt and cinder in the winter ruins permeable asphalt. Not sure about concrete, we try to avoid that altogether for cost reasons. Also the asphalt is, as he mentioned, a special mix that costs more to produce and place so in the end it’s just not worth it except in rare circumstances.

[@leddaudet2350]

And another concern would also be mold growing inside the pores of the concrete

[@TomServo3006]

Led Daudet why’s that?

[@Missingllynx]

You have to vacuum it regularly and use straight salt (no sand or grit) for deicing. Not that sand melts ice anyway... One advantage is when it's warm during the day and cold at night, slush seep through instead of refreezing at night.

[@digvijaysinghrana3351]

During my childhood I had this idea of a road pavement which will allow water to seep into the ground instead of directing it to sewage. And I'm blown by the thing is that someone made it.

[@johanprb357]

The lack of googly eyes made the topic hard to understand.

[@KingJellyfishII]

Instructions unclear, accidentally poured my concrete onto the ceiling due to lack of googly eyes

[@vaderconstantine]

agree

[@gensuave1]

That, and his alliteration of the letter 'p.' I found myself bracing for the next word and couldn't focus on what Grady was trying to teach.

[@_Solaris]

Oh yeah... no googly eyes

[@seanriopel3132]

His tongue was filling that role.

[@drockjr]

Most STEM videos are boring, long, complicated, and just terrible to learn from. With yours, I can easily smoke a bowl and drift away to your soft, knowledgeable voice, and the distant audio track of dreamland. -----All while actually learning and retaining the interesting subject matter. Like your video on Weirs or this porous concrete. I don't think anyone woke up this morning thinking *hmm, I really want to know more about this..* So kudos for engaging us, entertaining us, but more importantly taking your time and effort to reach those around you. You truly seem to love the subject matter and it shows. Thank you for all you do!

[@Piracanto]

Very interesting and wholesome with the kiddo! In Mexico we use the poor man's alternative: Gravel.

[@RoySATX]

I havent been to Mexico in some time, but when I was there I saw a lot of paving stones in use and being installed. Every time I went I saw the same areas under constant work. As soon as the pavers were laid they started falling apart, so it was a never ending work site. At the time I considered this a somewhat insane idea, but looking at it now I think it could be modified in such a way to be a practical design method.

[@mayoofm6049]

xDDDD

[@andym7165]

Mexico roads be like: ------___--_--_-^_^>___------^---^

[@jeffreypierson2064]

Your results may vary, depending on type of soil. Add water to the subsoil and you may get mud. Then the car drives on the gravel and gets pushed into the mud. Now you have spent money on gravel that has disappeared into the mud.

[@truckernation7886]

Cobblestones

[@sebastienwells7359]

you and project farm are my absolute favorite informational channels

[@asdffjsdjasd]

Grady saying "OG" made my day. Also, congratulations! You have a lovely family.

[@gur262]

Would be cool to hear about noise barriers next. Reflective, absorbtion, earth, bushes, concrete, etc

[@THEmickTHEgun]

This channel is one among a few sources of content and information that encouraged me to hopefully study engineering next year. Thank you, you are inspiring many of us.

[@erik365365365]

“Do you think my camera is going in slow motion or are you just that slow at cutting shallots?” What a whip

[@thestructuresguy8355]

The first time l learned about permeable pavement when I was a kid I thought it was some kind of trick or magic but when I studied it more it turns to be another way of using concrete. Thank you for you the great video as always

[@g.m.2427]

It's still magic, only now you know how it's done

[@reigyst]

Also a callout at the opening 0:14 to Hartford CT's skyline :). Very happy to see it making it to this channel

[@dascandy]

Congrats on the little one! In the Netherlands most of the highways are made from permeable road surface. Come take a look when you can! It's a nice surprise every time I drive home from Germany or Belgium when you cross the border, when it goes from a wet road to a highway instantly.

[@FurnitureFan]

Maybe it makes a difference that the Netherlands is a flat country? I grew up near mountains and when the local town roads flooded, everyone bypassed the areas by driving up through the mountains.

[@iyt6407]

@@FurnitureFan No it works everywhere, there are also more hilly parts of The Netherlands where it works fine. In Germany there is a mountainous part between Frankfurt and Munich where they applied it and it works very well!

[@aVeryIntelligentDog]

I work in construction for a company that is certified to install permeable asphalt and concrete (you actually need certification to do it where I live). Permeable asphalt/conrete still has a lot of room for improvement and there are many reasons why you don't see it more often. 1: Cost: It is anywhere from 3x - 5x as expensive per square meter, due to a higher quality aggregate being used, and a more time consuming installation process. 2: Maintenance: Sweeping alone will not prevent the asphalt/concrete from getting clogged, and it inevitably will get clogged over a certain period of time. A powerful pressure washer helps, but it would require a huge amount of time/water and it also just pushes a lot of the dust into the lower stone layer, which can become clogged over a much longer period of time. However, the pavement probably won't last long enough to experience that because- 3: Durability: Permeable asphalt/concrete is simply not as durable as conventional asphalt/concrete. The older it gets, the more easily it will crumble apart, and you will start seeing individual rocks breack off pretty quickly if the surface gets a lot of traffic. Permeable pavers work better in terms of drainage but they're even more expensive and more costly to maintain. It's a great idea but it will take some time before we could improve the technology enough to be practical for high traffic roads.

[@arthurbdt2329]

How can you improve asphalt technology ? Porous asphalt has existed for a long time and there has been no improvements.

[@zoravar.k7904]

@@arthurbdt2329 There have been plenty of improvements to durability and noise performance. Just look at how far the Netherlands have gotten since they started mass adoption of permeable concrete around 1995

[@jonathanorlando1294]

Grady finally got around to talking about grates, that is great!

[@gareth-stuartogg7887]

Best thing about practical engineering is that when a video is sponsored it's mentioned in the title card briefly then in more depth at the end of the video. The way sponsored videos should be!!! The content is always first on this channel and many more KZbinrs need to take note of Practical Engineerings approach to quality and viewer enjoyment

[@yannicmeyer421]

Congratulations on becoming a dad! Great vid as always :-).

[@Langevloei-NL]

Seeds get in the little holes and presto grass starts growing, even trees. Roots are very strong. Also, water inside the holes freezes in winter and expands, breaking the asphalt/concrete apart. We use ZOAB (Zeer Open Asphalt Beton) in The Netherlands for many years on dikes and elevated highways.

[@grantflippin7808]

It also accelerates road destruction and has a higher repair costs

[@hockeylance36]

Perfect for Phoenix where it never gets below freezing

[@mattalley4330]

​@@hockeylance36 Freezing temps are extremely rare in Phoenix, true enough, but weeds taking root in such pavement could still be a problem.

[@Nuggie_terpfessor]

I would figure they’d get clogged with dirt as well.

[@MartVan]

@@grantflippin7808 It doesn't you just resurface the surface every few years. That's how they do it in the Netherlands.

[@corthew]

Permeable pavement works by allowing the water from melting snow to seep into it so that when it refreezes the entire pavement becomes gravel which can be more easily removed with a loader.

[@phineas7423]

I would like to thank you for putting the sponsors in obvious segments which are seperate from the rest of the video, it makes them a lot easier for a sponsorblock user like myself to manage.

[@wich1]

I was wondering about this when watching your potholes video. Here in the Netherlands permeable pavement called ZOAB is quite famous, even many “regular” (non-engineer) folk know it although they often are misinformed about the details. ZOAB is Zeer Open Asfalt Beton, or very open asphalt concrete in English. In contrast to what you said this is actually heavily used on regular roads and highways that receive medium to heavy traffic. I wonder whether we have much more road maintenance because of it and/or whether we have found ways to fix the problem.

[@ietsbram]

According to dutch state standards we replace zoab every 11 years instead of the 19 for "normal pavement" assuming both are under a lot of normal weight car trafic

[@ahmedyassir5569]

I think it’s more of a safety concern; to prevent vehicles from skidding considering how much it rains

[@staalman1226]

@@ahmedyassir5569 It's probably more to prevent floods or rising rivers than for skidding (Misspelled "rising" at first)

[@cghoward70]

The Netherlands can’t afford not to. A large portion of the country is very close to or below sea level. The flood plane is everywhere.

[@ianjung2683]

I'm doing a project on stormwater runoff in my school, and this video really helped me to understand permeable pavements. Thanks!

[@mariodidier001]

That bridge shot at the beginning clearly shows how changing lanes slows down the traffic and produces a wave of slow downs.

[@LadyAnuB]

It's traffic from the western half of the Bay Bridge, westbound going into San Francisco.

[@watchandjewelryloft4713]

I absolutely hate that we don't teach and strictly enforce this simple task. Not only is it ridiculous to deal with, but who knows how much fuel it wastes, and with that emissions released into the environment. Add to that, many traffic signals that are extremely inefficient.

[@RoySATX]

Lane changes only slow traffic when the distance between two vehicles is less than a lane change requires and space must then be willingly granted or forcefully taken. And since both the person currently occupying the space and the one wanting to occupy the space assume the other is in their way and impeding them unnecessarily they end up jockeying position and impeding all the traffic behind them, further compacting their following distances. Lane changes aren't the problem, they are a necessary function of traffic. Impatience and not allowing proper distance between vehicles is the problem, and that is a phsychological problem more than an engineering problem. If appropriate following distance was maintained to allow lane changes, especially at ingress and egress points and at bottlenecks, traffic jams would cease to exist in most cases. Traffic would slow down, sure, but not come to a complete stop. Instead of having horns to blast at othes, vehicles should have horns that blast the driver whenever they tailgate.

[@williamzycinsky4720]

I'm always impressed by the fact that he can a four-minute intro into his actual topic of the video, the most interesting thing I've seen that day. Keep up the great work man.

[@ACivillage]

I was actually enjoying the ending advertisement part..

[@theskig]

Me too.

[@saleplains]

@@theskig i liked when she made fun of his knife work

[@kevinjanicki3973]

@@saleplains Tell me when to start recording.

[@thecypher7607]

Single-handedly giving me more appreciation for engineers and the endless stream of cr@p they have to deal with just to build something as seemingly simple as a road. Props my dude. 👍

[@trcostan]

I would argue that bricks are the OG of permeable pavement!

[@RAkers-tu1ey]

Too true! But, have you ever seen the maintenance needed for brick and cobblestone paving? Talk about rough roads!

[@danielloup9373]

R. Akers I’ve seen what it takes to fix both concretes and I still think cobbling is best for most residential roads.

[@TheOfficialOriginalChad]

“Some may call it the OG permeable pavement: steel grating” *subscribes

[@niuriver]

Thanks!

[@NameNaameNameeNaamee]

Congratulations on your little engineer! It shifts your life quite a bit doesn't it? :) Godspeed for you and your family! And - as always - this was a fantasticly well made video!

[@vMixMasterJayv]

Ayyye That Big Yellow Taxi reference! Don't think I didn't notice! I love your videos!! Keep them coming! The format and production of the videos is fantastic and your visuals really help me to understand things love your work man!!

[@jaysonl]

"Special considerations" in colder climates, indeed. My first question when I saw this video was "Huh? How is permeable pavement not ground into gravel when ice intrudes?"

[@weldonyoung1013]

The salt destroys it before the ice can form. But then there is beet juice.

[@servant74]

Some additives can add an 'elastic' quality to the concrete. It doesn't solve the freeze thaw issue, but it helps.

[@garcjr]

Most surfaces of permeable pavement I've seen are overlayed on top of asphalt or concrete. The permeable pavement is used as a wearing course.

[@weldonyoung1013]

@@garcjr , sound like you are pointing to a different produce like "top coat" or "chip seal" which usually have a short 'life-span' and are used to extend the useful life of the roadway. Some may only extend the roadway for a few years before complete maintenance is needed. The "chip seal" would look very much like permeable asphalt, but without a means to drain through the bottom will not function that way.

[@garcjr]

@@weldonyoung1013 What they pave here usually on highways is a one to two inch layer of rubberized asphalt which is a permeable pavement. It's placed on top of a base layer of asphalt or concrete. The DOTs here strip it down about every ten years and replace it when the pavement looses it's ability to reduce noise and drain water. The water drains into the rubberized asphalt to the concrete surface below. It greatly reduces [eliminates] the spray effect from cars. The soil here (in Arizona) you wouldn't be able to lay the permiable pavement directly on the ground the soil's too dry and would reduce the lifespan of the surface above.

[@konman36]

Back in college I sat in on a Civil Engineering lecture at The University of Michigan with my GF at the time (I was a nursing student). Although I had zero interest in Engineering, the lecture was about porous concrete and I never forgot the lecture.

[@XavierRaphael]

Video: “Includes paid promotion” Me: ok KZbin: here’s an AD!

[@randommcranderson5155]

the "paid promotion" disclaimer is because many youtubers were slipping in promotions without letting their audience know they were being paid to promote something. The disclaimer is to keep them honest. You know youtube ads are youtube ads.

[@sandrom.1992]

I was very happy to see such an excellent and high quality video about this one. I'm writing my master's thesis about reinforcement of road shoulders with permeable pavement. It's a very new topic for our university. Fun fact here in germany permeable pavement is called "open-pored concrete" (offenporiger Beton).

[@Ally-Oop]

“When you pave paradise to put up a parking lot” he looked so adorably smug with that reference haha

[@MrEazyE357]

I met them once in a TCBY Yoghurt in Nashville when I was in 7th grade. The lead singer was a dick, especially considering we were 5 kids just telling them we liked their music. This was like 25 years ago btw.

[@chickey333]

Crushed pottery cull is an ideal stone reservoir material if you can get your hands on enough of it. It's very open graded, it's very angular it drains instantly and it is extremely stable. It makes a very good underdrain for any purpose.

[@Mr.Adequate]

Every time it rains there is about half an inch of standing water on my school's recently installed "permeable concrete" thanks to our concrete science technology majors.

[@jamesengland7461]

Adorable baby! Congratulations!

[@vadenummela9353]

As a Finn. This looks like a very "californian" solution. Its "the perfect replacement" except in 90% of cases. In Finland every single one of these installatios would fill up with water and crack from freezing every year. Unless theyre like heated, which means even more cost and constant supply of heating, only near buildings.

[@richardschofield2201]

Nah, we use this stuff in the UK and it freezes in the winter a fair bit. I've specified permeable concrete a few times. It's permeable so when the water freezes it can expand through the pours and doesn't crack. Normal concrete is a problem as water can freeze into cracks with nowhere for the water to escape.

[@eklectiktoni]

You'd be surprised, it actually works in a variety of climates. It's starting to take off throughout the US.

[@comcastjohn]

Great channel bud. Thank you for sharing. Hard to find quality and educational stuff on tv or anywhere now days.👍

[@jasonhalljaxyt]

8:40 CONGRATS Grady

[@izimiger8924]

I dunno how you do it Grady, you're able to convey enthusiasm and professionalism in your videos without being obnoxious or over the top. Stay awsome Sir, and keep up the good work!

[@luigigaminglp]

Just watched this video, immediately got an idea: What if we keep the road itself impermeable, and make the sidewalks permeable entirely - since if there is little water to begin with, that will just drain as soon as it hits the sidewalk border, and if there is quite a lot more water the drainage effect also increases since more water = more permeable surface area... And since the sidewalk doesn't require to be nearly as powerful as the rest of the road...

[@alexsis1778]

Love the fact i got an ad for a water permeable paver product with this video.

[@Hypercube9]

"Tell me when you want me to start recording." LOL Your wife's awesome! 😂

[@aldenconsolver3428]

Would really enjoy a longer series of videos on this more nature friendly surface treatments. This is an excellent start.

[@firearmsstudent]

This video is brought to you by the letter "p"

[@ameyd3728]

Public money

[@VeNoM0619]

You see his Pink Pants during the Paid Promotion at the end?

[@honorarymancunian7433]

Someone needs to do a version where the video speeds up 1% every time a syllable beginning with a hard P is uttered.

[@MrMatteNWk]

I think I'll have to take a "p" kzbin.info/www/bejne/nqu6lYGLnLSneKs

[@johngold5214]

This is the man that commands attention at all the industry conferences. Fantastic video!

[@zoogoo404]

I've never been so early. Always appreciate your content PracEng!

[@dalfifran7572]

*"They paved paradise and put up a parking lot"* I love that reference you made to a Joni Mitchell song.

[@Kaiwala]

Gotta be honest, when answering the questions about this stuff in my construction BTEC I had bumfuck no clue how this stuff worked. Good thing I still passed or else I'd be dusting off the old time machine by now...

[@52hahgz]

This kind of material is being used for paving major roads in my country. It is very efficient in reducing aquaplaning and improving visibility during major rainstorms, but it also increases tire noise making trips less comfortable.

[@claypunk7718]

❤️ for the Joni Mitchell reference

[@derpionderpson1424]

Got to say I love when a video from you show up in my recommendation, always some awesome info to get.

[@jimmysgameclips]

Me: 'Not sure how much I'll be into this one- oooh'

[@Oli-Johnson]

The amount of words beginning with P in this video is Perfect!

[@grimbles39]

I see thirsty concrete is making a resurgence, all of a sudden.

[@JoeyJoJoJrShabbado]

Your early, it’s not 3am yet but I’ll watch.

[@drvanon]

Side note: your wife has a really nice voice, you should recruit her for the voice overs!

[@BigBrex0124]

Side creep : don't f*king say that

[@Rampman]

I love watching your videos. I am not an engineer but I learned a lot of engineering stuff, how materials work and many more

[@A_Tempest]

I haven't watched the video yet, but what is permeable concrete's performance under freeze thaw like? I would imagine it's very susceptible to cracking

[@mfbfreak]

It is. Highways in the Netherlands really suffer badly from it, but the alternative is a higher risk of aquaplaning. Lots of rain here, so they just choose to replace the road surface more often.

[@schirmactueventuality6243]

Typically it does pretty well with freeze thaw since it is full of voids for water/ice to expand to while freezing. The reason normal concrete cracks from freeze thaw is because the water/ice has nowhere to expand to which is why the traditional solution is to put air voids in the concrete. The only real concern with its use in an environment where you get freezing winters is the porous concrete can be damaged more easily by snowplows since it is much more loosely bonded together. A good example of its use in freezing weather is the Ford factory outside of Detroit Michigan where F150 trucks are made. They have a large parking lot made of porous concrete that has held up pretty well over years a Michigan's extremely harsh winters.

[@mfbfreak]

@@schirmactueventuality6243 In theory, you're right. In practice, every winter where there are freezing temperatures after rain or water from melting snow gets into the road, we need emergency road repairs because of the ZOAB breaking up. Perhaps we have higher standards when it comes to road quality. On a 200km stretch i used to do every month or so, i couldn't find one single pothole.

[@KorawichKavee]

This is also why keep street low speed is more than just reducing damage of crash in a neighborhood but also about rain runoff opportunities when using this kind of asphalt.

[@BusterSwordsman]

A couple things to keep in mind. 1, pervious pavement requires a special street sweeper for road maintenance, one with a strong vacuum. Even then, it does not pick up 100% of the debris in the pores. 2, in the places that it has been installed in my city, the pavement sits on top of roughly 2 feet of drain rock. This means that utilities in the area might have to preemptively go through and lower or reinstall their structures, which could cost 10's of thousands of dollars, depending on the size of the area being replaced. Plus, I would HATE, to have to break that street to fix something like a broken water main.

[@EyeofZai]

while there are additional costs associated with permeable pavement, there are also ways we save significant amounts of money. by utilizing it effectively, we prevent damage from flooding. by ensuring drainage on roads during storms, we can potentially driving safer and prevent accidents. by reducing runoff, we help to prevent phosphorus and nitrogen induced toxic algal blooms that prevent recreation and degrade habitat necessary for commercial fisheries. we can increase the amount of water infiltration into groundwater resources, we prevent often dangerous and costly erosion. in other words, if utilized widely and effectively, and in conjunction with other solutions (regenerative agriculture, more livable cities, etc) it would actually save a lot of money. would it single-handedly solve these problems? no. but it’s a lot better than what we’ve got going on right now.

[@creamshop]

I must be a Nerd, I Love videos like this that feed my brain

[@permeus2nd]

6:26 I would imagine that this would only work in locations that are never expected to have ground ice form as I can’t imagine it standing up to a standard British winter 🥶

[@itsukarine]

having just watched your sinkhole video, im trying to figure out why permeable concrete wouldnt lead to an increase in major issues like sinkholes or lesser issues like potholes (though you did mention it, briefly) would the water not really erode much since it's "trickling" into the ground instead of running like it would from a pipe, and thus removing a lot of its erosive qualities?

[@CupolaDaze]

I remember watching this video when it came out. Now the company I work for has done two permeable pavement parking lots. Large excavation for the subgrade rock to filter the water. Solid concrete baffles to section off the underground, and pvc pipes to facilitate that water leaving if it can't permeate the soil.

[@Timsturbs]

0:24 krymsky bridge near gorky park 3:12 lugniki

[@guymoreau609]

0:36 Chaudière bridge between Ontario and Quebec, Canada during the 2019 spring floods. Overflow from very close hydro dam.

[@joaocoelho9229]

The alliteration in this video is A+

[@alexanderx33]

You covered several of them but there is one more MAJOR limitation of permeable pavement. It wears really really fast. Even just foot traffic can turn it back into gravel in a visible way in a few months. The problem is that by removing the sand from the concrete mix you remove the vast majority of the contact area between the rock particles resulting in concentration of load on the teeny portland cement bridges. As a result it isn't a long term civil solution, ie not a civil solution, lol.

[@jacktjong1266]

*looks at the entire country of the Netherlands* Here in NL all our public roads are made from permeable asphalt and the road surface is near flawless wherever you go. And this is despite us enduring constant rain and freezing temperatures in the winter.

[@garyh4458]

I love it when a Grady video pops up in my feed!

[@tamaslapsanszki8744]

USA: we use permeable pavement to help the water get into the soil Eastern Europe: what's pavement?

[@ritwikgaur1858]

Why it is so??? 🙄

[@tamaslapsanszki8744]

@@ritwikgaur1858 because it's an important "promise" in election years. You can't promise paved roads and new highways if they are already built. So they aren't built, but promised every 4 years 🤣🤣🤣🤣

[@pb730c3]

This was tried for a parking lot in Lansing, MI. It has recently been replaced with traditional asphalt. It didn't do so well with our freeze/thaw cycles and plowing. They ended up patching parts with concrete but It basically turned into a loose gravel parking lot.

[@KOTYAR0]

*cries in Russian, having to change all of asphalt on the road every 2 or 3 years*