Road improvement project 6

June 2014

[Thumbnail pictures are linked to larger ones.]

Catch basin cleaning claw The next day a couple of guys came along with a special catch-basin cleaning truck, basically a dump truck which features a small crane over the bed that can swing out and lower a big 4-bladed claw down into deep holes and grab out junk and sediment. Except that these were brand-new and there was nothing down there! I'm not sure why they came by but perhaps it's the contractor for the town in general and they'd gotten notified to add this new place to the rotation. I'm guessing here.

Anyway, they checked both basins and painted splotches of bright green on the grates before leaving.

Another paving-recycler machine I was helping work an event elsewhere the following weekend, and during the prep for it the Friday beforehand a little roadwork was being done nearby. They were using this -- another Wirtgen pavement recycler, this one with little tracklets instead of wheels and a big conveyer-belt option that could unfold. They didn't use the latter here, but it hints that the path for the machine's output can be switched between coming out the bottom or being sent over to a truck for removal or further processing. It was rather fun to actually know what I was looking at here and tell the folks I was working with "they had one of *those* on my street a week ago!" and describe what it could do.

    Water gone astray

During my travels in and out for the event prep I had noticed a wet area near one of the catch basins while driving past. Since we'd gotten a few rain sprinkles on some recent overnights I attributed it to that, failing to take any specific note that the other grating was dead-dry. As there didn't seem to be more work activity going on after that weekend, I decided to head off and help someone with a little kitchen cabinetwork. The wet area was *still* wet, so on the way out I stopped for a closer look and discovered that there was a larger problem going on -- the puddle was actually originating from about ten feet away from the catch basin, where a little trickle of water was *bubbling out of the pavement*. Oops. The sustained wetness was evidently from a water pipe leak somewhere underneath. The catch basin on that side was already full right up to the level of the pipe to the infiltration area, while the other one was still empty.

Well, this would be a bit of a setback. It had clearly been going on at a low level for a couple of days, and if they weren't on it by now I figured they'd start fixing it some other morning soon and bopped off for my day of improving someone *else's* home for a change. In the middle of all that fun with tools I got a call from my neighbor. He and I had been sharing concerns about the brown water we'd been seeing from the taps and toilets recently, and the town utilities manager had been out to collect a couple of samples for lab analysis. Everyone attributed the discoloration to some normal backflush-pit maintenance work they'd been doing down at the pump-house rather than any of the road construction -- a little iron and manganese is perfectly normal and safe for the water around here, and sometimes certain cleaning operations temporarily kick the "rust" levels up a little. And after all, the water main work for the subdivision had been done months ago and there shouldn't have been any lingering effects from that. On the other hand they *had* done all that soil compaction more recently, however low a level they might have kept the roller at. Something in the interim, possibly coupled with minor pressure surges along the main from the pump-house activity, apparently loosened up enough to start leaking. The unregulated water pressure around here runs around 90 PSI with peaks over 100, nothing to sneeze at and connections have to be *tight*. That's why I got a regulator. Anyway, the neighbor said on the phone that someone was back doing work on the street and the water guys were wondering how to test if *I* still had water service since I didn't have an accessible external faucet at the time.

Argh. The *one* goddamn day anybody was back to do work when I was off-site, assuming nobody was going to attack it that day. But apparently this had become enough of an emergency that the town guys were on it that afternoon. I encouraged said neighbor to go out and get some pictures of what they were doing.

Digging to find water leaks He did, and we transferred them from his phone the next day, but he didn't really capture any of the good details. Regardless, it was clear that they had to knock a couple of big holes through the nice new paving to get down there and figure out what was going on. Fortunately it was still only the binder layer, so they weren't destroying a finished surface.

Water main exposed *again* More of the water main got exposed but even this doesn't show anything particularly distinctive, and this isn't where the leak was anyway. But I got more of the story from the town water guy when he called the next day to make sure I still had water.
Remember the "mystery pipe"? Now it wasn't such a mystery anymore. It turned out that way back in the day, like in the fifties or so, the water main had gotten extended a little down the street. Still a dead end, but needed to serve a couple of newer houses [probably including mine] that had gone in since the original installation. What had originally been done was what they call "spaghetti piping", where feeds to homes came off near the end of the main and ran a little further down the street before turning toward properties. Some of these evidently ran quite a ways along the same line of the road, and in those days of less rigid building codes were often an oddball diameter. When the main had gotten extended, feeds to serve the existing houses had gotten replumbed directly into it [probably back from the individual shutoffs] but the old pipes had simply gotten capped off where they lay, rather than back at their origination point in the old section of main. So they were still there under the road, and still with live pressure inside. For fifty-plus years. The town had no documentation on any of this.

Nonetheless it finally explains why the mystery pipe was still "hot", just downstream of where the old main ended. And they'd simply capped it where it sat *again* during the catch-basin work, which did feel like kind of a quick-n-dirty redneck fix at the time.

The disturbance of construction above had apparently caused one of the old hookups to start leaking, so it was time to get in there and find all that old stuff *at* the main and do a proper repair. While this would have likely produced a fascinating subset of pictures involving sloshing around in knee-deep muck, we're just going to have to envision it. By the time I came home that day they were all done, the new holes filled back in, and nobody around. More importantly, the street was dry. Oh, and I still had drinking water.

And there's living proof that a couple of good pictures could have told the thousand words you just read.

Lowering hole surface The repair holes had simply been backfilled with dirt, but now they had to restore an equivalent binder layer of pavement. The town guys returned with a completely different collection of equipment, and first scraped out about two inches of dirt from their work of yesterday.

New holes ready to repave These only sat open in a hazardous fashion over their lunch break, but they made sure nobody would absently drive into them in the meantime. Not that "absently" and "driving" should ever occur in the same sentence, but <insert giant rant about entitlement and cellphones here>.

Pavement to match binder They came back later with a small load of asphalt and filled everything in back up to the original binder level, almost like nothing had happened and once again ready for the final paving layer -- this time for real!

They brought the *cutest* little roller along, which included vibration capability that was modestly used to mash down a few high spots. Nothing like the massive dirt compactor, though; I could barely tell when they used it from inside the house.

Rain into catch grate Friday the 13th came along and brought an afternoon of fairly heavy rain. Finally a nice test for the drainage system. The catch basins were already well-laden with pollen sludge from all the oak threads and green dust that had been flying around. A lot of that was floating, meaning a certain amount of crap was heading off into the infiltration pits as this is a non-baffled system.

Of course the water started puddling around the grate again, because it was sitting proud of the binder surface. It would eventually be just below the final surface level, but for now the bottom inch of water had nowhere to go. Since this situation can come up on any construction job, I wondered if a few small slots cut an inch or two down into the grating frame would be a useful design feature that could allow for fully draining puddles in this temporary arrangement without compromising the strength.

At this point I had a much better feel for how planning related to a paving job goes. There's quite a lot of anticipation needed to accomodate every possible feature that the asphalt layers will touch, and all of the grading and crowning has to be correctly maintained throughout. They had already pushed out a little beyond the originally intended edge, but that was okay as for the most part they had leeway to do so up and down the road and only had to work around some very minor obstacles.

Things again went quiet for several days, as once the binder layer was down and the various penetrations through it sorted out there wasn't any pressing need for the final phases of the job yet. Traffic came and went over what was there, much of it going entirely too fast [as expected, see above about "entitlement"] although calmed a little bit right at the low point by the cones still sitting on the drainage structures. And as we were still in pollen season a lot more of the organic crap fell freely onto the new surface.

A notice showed up from the town public-works director one morning, warning that the final paving layer was really and truly going to happen on a specific date. The important message was for abutters to please plan ahead and avoid driving on it prematurely and/or wait several hours before venturing out and be really gentle while doing so, as tires turning too sharply would chew up the fresh surface. It seems that the vast majority of drivers in low-speed maneuvers crank their steering wheel around with the car sitting still, which simply grinds one spot on the tires against the pavement. There's no point to that unless you're stuck in a *really* tight parking spot; even there I will generally try to have just a little forward/back movement while swinging the wheel to make the tires actually *roll* while turning.

    The last chapter

Bank erosion near wetland I wandered out nice and early on the specified morning, this time ready for the prompt start that the paving crew would get. Their gear was already rumbling in through the subdivision access. Near the new intersection I noticed that the town conservation department's insistence on erosion barriers was a good idea; those same heavy rains had definitely brought a bit of flow off the pavement which would have eroded more of the bank into the wetland if not deflected away. This whole area would eventually need some riprap or something on the bank.

Marking centerline They started moving equipment and marking a nominal centerline for the paver to follow. Not position-critical, as they would just be matching the halves again.

Leaf-blowing stuff off the street By this time a lot of organic muck had collected on the binder, which could interfere with asphalt adhesion. Somehow I thought they were going to bring in a vacuum sweeper and do a really thorough job of cleaning it off, but all they did was have a guy take a quick pass all the way up with a leaf blower. Right into everyone's yards, which I thought was a little inconsiderate.

Small asphalt delivery at headend A smaller dump truck backed in at the head end where work would start. The cut between old and new is pretty obvious here; all this would be height-matched by the final layer.

Curb forming machine The truck was actually there to supply a specific mix for the curb former instead of the main roadway. I hadn't seen one of these in operation before, but after reading about how they work it totally makes sense. This was the only spot where a conceptual "curb" would be placed, if for nothing else than to keep drivers from cutting the turn too close onto the abutter's strip of grass which he said happens fairly frequently. See above about entitlement, inattention, and bad driving.

What they couldn't do was *compact* the curb assembly, relying on the machine to extrude the mix under a little bit of pressure and then for it to just set in place. While hot, it was still fairly delicate.

Starting main paving run This meant as they started the main paving run, the guys had to be really careful to not step on the curb part while tending the machine. This led to some amusing hopping around.

New layer above binder Almost-cross-section of the new layer on top of the binder. I guess adhesion was good enough despite the sketchy cleaning.

This time they laid shorter segments and did both sides more or less at once, to leave all of the new surface fully behind them and avoid traveling over it.

Asphalt tamping shoes Here's a brilliantly simple method of small detail compaction: a pair of flat-bottom shoes which someone could simply walk the surface with and stomp down the high spots. The guys carried batches of diesel in old detergent bottles almost everywhere, to keep wetting down their tools with and prevent sticking.

The bouncy thing Slightly larger-scale compaction was done with what I called the "bouncy thing", which does just that and looks like an utter joy to operate -- well, in the sense of rattling every fiber of one's being if that's what you're into. I wasn't quite sure why he was bothering with this edge as the paver was about to pick up and continue here and the big rollers would take care of blending it all together.

Approaching catch grate Paving right over (covered) catch grate
Work proceeded fairly quickly -- these guys don't mess around, and their foreman was being pretty merciless about keeping them moving. Soon they arrived at the low point. They had special plates to pop into the catch basin gratings, with pins down into the holes to keep them in place; after these were dropped in they coated everything with diesel and then paved right over it all, which at the predetermined height was only a very thin layer on the drainage features relative to the rest.

Clearing off manhole cover The plates were immediately pulled up afterward and the asphalt around them and over the manhole covers trimmed aside, the easiest way for doing the latter by simply kicking it off the cover and letting the roller come along and squish it into the surrounding area.

Finding the curb box cover They also sprayed down the top of my new water-shutoff cover with diesel and then went right over that too, and paused for a moment to uncover it again before rolling that strip. This put its top about the expected half-inch down from the new surface.

Clearing asphalt out of water cover As the uncovering job was far from thorough, I made sure to scrape the rest of the asphalt away from the cover and holding bolt while it was still hot. I also thought about how to improve drainage past here, as the road crown would feed me some minor amount of water, and as a start I cut a little escape channel out to the edge. I figured on coming back later and seeing if I needed to finalize a better water path around this.

A couple of weeks later I hit upon what to try as a good test solution. Fine dirt had already settled in around the rim and the bolt head and had absorbed some of the diesel, making sort of a water-resistant oily granular putty around where joints in the cast iron were. So I dribbled a little 90-weight gear oil around the same areas and patted a little more fine dirt into the whole thing, which would form a sludge similar to what we find on old greasy engines -- that could maybe protect the metal a little more and shed water aside into my little drain trench but would be easy to pick back out should the cover ever need opening. I would keep an eye on it over the next few years to see if it needed anything more than that.

Shoe-tamping a driveway berm Flattening the berm with a rock
The way that the grading worked out left the binder layer sitting a little higher than the dirt in my pseudo-driveway instead of below it, and now the final road surface was even higher. Rather than letting the crowning dump water into my yard they fashioned a little berm at the edge of the asphalt across the opening. "Shoe Man" came by to shape it and tamp it down a little, but for some reason left a fairly sharp point at the apex that I'd have to bump over with the car. So after he was done I took a handy rock and thumped the point down all the way along to round it off a little. Immediate proof that the grade was correct on this small scale came from watching the dribble from the roller flow across the opening toward the low point instead of coming in onto the dirt.

Berm to direct water past driveway The neighbor right *at* the low point got a more extreme berm to direct water to the catch basin instead of down his driveway, solving one of his long-term headaches at the expense of having his own little bump to drive over. Which, I might add, he did before it became decently solid as he had to go out to an event and hadn't planned around the well-publicized paving. The developer's folks and the engineer were kind of annoyed, mumbling stuff about "ruining the job", and sent someone back to reshape a couple of things before it was too late.

Stakes are gone As the final layer advanced toward completion down near the intersection, one of the developer crew pulled all the bright orange stakes we'd been living with for weeks. I guess this meant that they were really done with this part!

Paving up to curbs Curbs had gone in flanking the intersection and road into the subdivision, so paving had to come right up to them but keep the correct sloped openings around the catch grates. The paver could lay down a first approximation pretty closely.

Hand spreading to curb Bouncy thing to tamp right up to curb
Final trimming of the joint was by hand, and the Bouncy Thing could compact it right up to the curb without risking any scrapes by passing rollers.

Three valve area They backed up over the area with those three water-main valve casings still sticking up at the spec height, and filled all that in with a couple more passes. Note the ever-present detergent bottle of diesel right handy on top of the paver...

Spreading liquid tar sealer Before filling in the center strips, a guy opened up a large bucket of some sort of liquid sealer and generously splashed it around all over the binder. This was presumably to help glue the layers together, which frankly I thought they might do over much more of the rest of the road perhaps using a sprayer truck to get better coverage. Here it seemed pretty haphazard, and I didn't quite see the point.

Checking drain level Final grades into the catch basins were level-checked along various axes as they finished up the rest of the intersection.

Sand over sealer joints The sealer goop found greater utility in gluing together the edges of the new and existing pavement in driveways and other join points, with a little layer of sand on top to allow passage over the sticky stuff. They did this just about everywhere that asphalt met asphalt including up at the road head end where the new section started.

Temporary berm filler They threw down a temporary dirt berm behind my opening to help the car get over it, and a few days later replaced it with a somewhat more compactable aggregate and took away the chunks of old asphalt that were still piled up at the corner. I told them I didn't really care about fine points on this as I was considering some sort of driveway paving job in the indefinite future after all the street work was done anyway.

Stop sign lower post They also installed some street signs for the subdivision that afternoon, where I realized that it's smart to do a base post into concrete and then bolt the visible part of the post to it as a separate piece later. This one would eventually become the stop sign coming out of the development.

OMG, it's a real street now So after all that, we now had what might be called a Real Street! While many of us liked the old dirt road for a variety of silly and/or backward reasons, perhaps this would be better long-term. And the town basically got it for free since the developer insisted that he wanted to do it as part of the project, undoubtedly influential on the final decision to go ahead.

_H*   140623