I wonder where this is. It looks like it may be Bernal Heights.

Grinding the streets first inch or two off. When they stop it's probably because of a man hole, storm drain or something they are trying to not damage and have to go around or do the hand work around it.

Street looks dark right after they grind because the asphalt underneath has sections that aren't bleached from the sun and what not.

Then they smooth it to pick up the bits left, the street gets white looking because of all the scratching to the layer they leave, or because there is concrete underneath. They do bridges like this...two or more layers of asphalt to take all the wear and tear and water damage. Then replace it every so often so the concrete lasts longer.

Curb sides take the longest because they don't want to break the sidewalks, and the machines can only get so close without putting too much pressure on them.

Then they spray tar down to help the new layer of asphalt stick to the existing and help seal out water. If they don't spray tar down on old surfaces, asphalt tends to stick to itself and will hump up and become uneven when the guys roll it to compact it and smooth it out. You still have to slow gradually to stop this from happening. It's why when you drive down the road on a new street and you feel little bumps, often times you can't even see them. But it's because the rollers are stopping and the asphalt is developing little humps where they are pushing the material ahead of them as they compact like a little wave. And if they don't seal out the water well, if it ever gets between the layers and freezes, the top layer will just buck up and crumble...and you have a pot hole. Why they are along the edges the most, because the water gets in between the sidewalk and asphalt and runs underneath the new layer. Or sometimes it can get between the seams of the new asphalt, where one strip meets another if they don't match them well.

Parking lots, and country roads would let this crew do many more times repavement than a street like this. Because of the sidewalks, man holes, constricted lane of movement, and having to maintain the height of the road to maintain the flow of water.

Country road they'd just put another layer of asphalt down and then put approaches (basically a gradual ramp) on the other roads and driveways so cars can get onto it. No grinding, no sidewalks and stuff to worry about. Or if the road is really bad. They'd put one layer to fill in all the holes, then another on top of that.

check out the big brain on porksandwich

(thanks for that explanation!)

It'd take about 6 months over here.

Yep, I'm in Canada and to see that done in hours is kind of depressing. I've never seen it done in 8 days, and that is no exaggeration sadly. It's something I've always noticed though between American and Canadian road crews. Up here, the same stretch of road or high way will be under construction for an entire summer(without exception). On road trips through the US, the crews working a road have plainly completed and moved on through several miles of new road in the mere time I'm on my vacation of a week or two. Props to you guys getting this stuff done the right way.

Might depend on where you live. Around here they often use 'trains' where the entire process is done with machines that are linked one to the next. First one grinds, a conveyer takes the ground pavement back to be mixed, next one lays down the fresh asphalt, next steams it, then a roller and finally it paints the lines. The whole thing moves at about 1km per hour.

Yeah, I see this frequently when travelling the states. I've never once seen it in Canada. Up here we seem to prefer sending in different crews for each job. So 30 miles of road gets torn up, and then sits like that for several weeks waiting for the crew that does the next stage, and then more weeks of waiting... Horrifyingly inefficient and it just boggles my mind we can't take a page from the crews only an hour south of us that are getting it right.

Recycled mix (using old asphalt with other "stuff" that can be put into mix to get rid of it..like rubber tires) doesn't lay as well as new asphalt mix or hold up as well.

Since old mix uses old asphalt, it typically has oil, gasoline, diesel, etc soaked into it. All of these substances degrade/eat asphalt over time. It's why they don't use asphalt around fuel pumps, because all of the constant and pure spillage would eat holes in it. Turns the asphalt gummy...goes right into it and sometimes thru to the sub-grade rock and then soil. Also motorcycle kick stands don't do well on asphalt, contaminated or not..especially on hot days. Asphalt will become pliable on really hot days and a focused direct pressure like a motorcycle kickstand can punch a hole into it that be deep enough to let the bike tip over. Use a wood block or piece of plywood to fix this and spread the pressure.

I used to work in the asphalt business, mostly rolling it. My dad worked in it more substantially than myself working on airport jobs, highways, etc. Many of those jobs won't allow old asphalt to be used in their mix. And they are big enough to force plants to switch over from remixed (old and new) to all new mixes. You'll notice that jobs done with the new mixes hold up much longer, look better, lay better, hold their heat better during the laying process, and come out much smoother looking and less "dirty looking" upon finish. I am guessing at this, but I believe it to be because the asphalt has more tar and less other chemicals and the tar is able to absorb any dirt you might pick up when you move to existing surfaces onto the new asphalt. Where the remix (containing old) has gasoline, etc breaking down the tar and less fresh tar to begin with, so that little bit of dirt you pick up transfers to the remix asphalt like a magnet.

Highways probably won't have as much surface area covered in long term spillage as stop and go traffic where it will be focused at the lights, stop signs, along edge of the streets where people park. But the highway will have big sections of highly contaminated asphalt where semis flip, car wrecks occur, etc. So these same sections if they are remixing it on the go, will end up with a bunch of really bad asphalt on or just after it if they don't throw it out.

And to clarify a few things upon incase people are unfamiliar.

Asphalt plants are usually multi purpose. They are usually a stone quarry with an asphalt plant situated somewhere on site. They filter and crush the stone into piles for sub grade work of various needs. And they draw from these piles to feed the asphalt plant. They do new mix and recycled mix (old mix) which I'll explain below. They also often times have sealer (the black coating you put on parking lots and driveways), I'll explain it below. Roofing tar, regular/asphalt tar, and crack filler..and I'll cover these below as well.

The plants have some human guesswork involved, they have to estimate tonnage and how much tar should be added. They screw up pretty often. It wasn't unheard of for us to get super tarry asphalt mixes where it was like goo coming out of the truck. Or no-tar mixes where it was just slightly black painted rocks. Or mixes where we called them "burnt" where they pumped in their cleaning mixture into the mix and it was breaking down the mixture to help get it out of the hoppers of the plant. These were usually people being trained who hit the wrong button without realizing it.

The plants have to clean the mixtures out of the hopper (where they dump it into the truck) to cycle over to a new mixture they keep in on-site silo looking things that stir and heat it. Which the silos also have to be cleaned at the end of the day or heated all night lest they hardened and stop up the whole thing. They usually stop heating all night as it gets closer to winter season because they don't do enough business to make it worthwhile.

Ok mixtures:

I didn't mention base mix anywhere...but it's why they typically have to switch over to different mixes, because places need base mix instead of finish layer....the layer you see when finished looks less rocky than base and is pliable.

Base mix = larger aggregate rocks, much more rocky. Doesn't have much fine rock in it. It's meant to be something you can quickly lay that will hold up the weight of heavy vehicles right away. Usually this is only used on fresh roadways where they are laying directly over rock sub-grades. It makes it easier to lay the finish layer smoothly, makes for a cleaner looking job by locking the rock and it's dust in...and is cheaper than using all finish. You can almost go from laying base mix to laying finish layer right on top of it with no delay. You can't do this with two layers of finish, because it's too pliable and it has to cool down for the heavy vehicles to drive over it without squishing it out and messing up the layer you just laid.

New mix asphalt = Tar mixture with aggregate like fine almost sand like rocks along with larger rocks to give it stability larger rocks are maybe the size of your pinkie nail at the largest. Tar is mixed throughout, the whole mix is constantly stirred and heated inside the plant, drawn into the hopper and dumped in a truck that pulls underneath. I am told that this mix used to be even better in the past, but now air regulations require them to "inject" their dust from rock crushing into the mixes so again this can cause the mix to be less tarry due to the dust being absorbed and they can completely ruin it by injecting too much.

SCAM ALERT: Look below remix as it pertains to both.

Remix (old and new) asphalt = Very similar to new mix, except they grind up old asphalt that they have sitting on-site in the stone quarry congealing into a big pile depending on it's contamination. This will depend on percentage they are legally required/allowed to put into these mixes. Less of the remix in the mixture, the better it is....less contaminates. Sometimes they even put rubber tires and other rubber products into the mixture. Although they don't do that much here. SOMETIMES it is desirable to have rubber in the mixture like running tracks, where they are springy. This is a special mixture, and it's a massive PITA to lay because it's really gummy and sticks to everything along the process.

SCAM ALERT: They typically do this to older people. But someone will stop and tell you they are working on a big site close, and they are going to have some extra material at the end. Usually you would dump this at the plant or somewhere you have set aside. They want to help you get a new looking driveway. They will lay the asphalt less than an inch thick. It will look really good when they finish. A year later it will be broken apart in most cases. Because they didn't tar, and they laid it too thin. You can lay asphalt thinner if you tar really well....but you want to lay it at least a inch and a half per layer or so. Sometimes you have to lay it thin near man holes and drains to not block water. So don't go crazy on somebody because of this if you see them doing it in certain places. Generally they try to average an inch and a half across a job per layer on finish. Thicker on base mixes since it has larger rocks in it and it has to be at least as thick as the biggest rock in it.

Sealer (the black coating you put on parking lots and driveways) - This is almost like a black paint in some circumstances. Some of it has chemicals, I think creosote, which react to the sunlight and cure it to seal it to the asphalt. Depending on what you buy, you may have to mix water into it to make it suitable for the task. Some come pre-mixed and you just have to stir. Usually you put two coatings on new asphalt, one coat if it's been sealed before. Sealer WILL NOT make your driveway last longer by any noticeable degree. It will make it look dark, and repel chemical spills to some degree. However chemicals will still penetrate as you can't clean up everything that drops. ALSO, sealer makes your driveway much slicker. This is why they don't use sealer on roadways, if they are using some kind of treatment it's something else because sealer fills in all of the fine holes in asphalt and makes it more slippery because of this..especially in the rain. Sealer has to cure for a couple days, you can't drive on it and it can't get wet. So listen to them when they say they don't want to seal it due to weather. Don't let them seal it in the spring or fall. Do it in the summer so it's nice and hot and not much moisture. Sealer looks more brown going down than black. But it cures to black.....it almost looks like chocolate cake mix. Dunno if they taste the same.

If you are sealing your own driveway, do not get it on you. It burns like a mother, I've gotten it on myself and if you don't clean it off right away it will burn you like a really bad sunburn after being exposed to sunlight for awhile. Some people are not bothered by creosote (if this is the correct chemical in sealer)...but better to not find out..because it hurts if you are.

SCAM ALERT: People will seal your driveways with motor oil or even too watered down sealer. They look very similar going down. There is no easy way to tell the difference besides knowing what they smell like. The first rain will turn your motor oil covered driveway into a mess. We have gypsies in the area pretend to be local businesses and pull things like this, it's bad. They disappear at the end of summer and the businesses are left with people pissed off.

Roofing tar - Runnier and less thick than regular tar. It's meant to be pumped onto roofs and run down to fill in holes and places water can get in. If you use this on your driveway, you're pretty much going to end up with a huge mess for years. Because it will continually heat up in the sun and liquify again being tracked into your house over and over and over.

Regular/asphalt tar - Use this, like in the video, along curb sides and between old and new layers to help seal out water and keep the layers sticking together as you put down the new layer. You wouldn't need to tar between a base and finish layer if they were laid a day or two apart because the base layer would heat up again from the finish layer and stick. However if the base layer is older..like a couple weeks or a month. You would probably tar between them. Anything else..you tar between...concrete, old asphalt. The only exception would be sub-grade rock, however sometimes you even tar this, especially if it's in a grade critical location...where you can't have the asphalt humping up even a little. But on a typical driveway, the rock layer has enough jags and spaces that a layer of asphalt will cling to it just fine.

Crack filler - You would use this before sealing your driveway, not after. You can also use it alone to fill in gaps in your driveway and try to seal out water. So it doesn't get into the crack, freeze and blow your driveway up. The best crack filler is rubberized, so it will expand and contract. Plus it also isn't as prone to liquify again in the heat and stick to your car tires and shoes. It has to be heated up substantially to liquify, but I've seen non-rubberized begin to liquify in direct sunlight on a 95+F degree day. I try not to step on the cracks on the really hot days, as I'd rather not find out if it's going to stick to my shoes.

^ fuckin a.

Yep, porksandwich wins the repaving bid for my driveway as well...

I think that I shall never see

a poem as lovely as a freshly paved road.

huhuhu
huhuhuhuhuhu

<butthead voice>
you said
crack filler

huuhuhuhh

They used to say letting gays work at the DOT would hurt productivity and pose a safety risk. These days they're all gay.