Perspective on $2.2 million road improvement job on Highway 6

I have found a little history on Route 6. The history of pavement in this area started in 1927 with six inches of Portland Cement Concrete Pavement that was placed on either the eastbound or westbound lanes. Just like today money dictated just how much work would be performed.

It was not uncommon back in those days for only one half of the road to be improved. Those of you who can remember back to 1927, will recall that one side of the road you were driving on would be concrete while the other side would still be gravel or maybe even dirt. I think that is the case here because in 1931, four years later, the highway department came back and placed another six inches of Portland Cement Concrete Pavement. This probably completed the other half of the road.

On the other side of Maysville, near the little town of Clarksdale, you can still find a county road that is half concrete and half gravel. This is an old abandoned section of Route 6.

If you talk to some of Gallatin’s MoDOT maintenance folks they will tell you that there are areas that have no concrete at all.

Road widened in 1955

Now we jump forward 24 years to 1955 (the year I was born) the road was widened from 20 foot to 24 foot. A two foot asphalt base was placed on both sides of the road to complete the widening. Then a wedge course was placed. This is done to level the road by filling in the low spots in order to bring the road back to an acceptable condition to put the next lift, or layer, of asphalt on it.The wedge course is usually placed to accomplish setting the profile grade of the road.

The profile grade is the slope of the road from center line. From the center line, the road drops so the road will drain. The shoulders are at a steeper slope so they will also drain. It is constructed this way so moisture will not sit on the road. Nor can it be too steep, because in an ice storm you wouldn’t be able to stay on it.

One layer of type “B” asphalt was placed and with the final lift of asphalt type “C”. The history I was getting my information from did not have depths of the asphalt but I am guessing that both lifts would equal 3 ¾“.

What makes the difference in the types of asphalt? One may be courser, like the bottom layer, then a finer mix might be placed on top for a smoother ride. They don’t use the IB or IC mixes anymore.

Jump forward to 1969 and 1990

You will notice I said jump forward 24 years the first time. Now we jump forward 14 years to 1969. The time line is such that a lot more of us can remember when this work was performed.

At this time a wedge course of asphalt was placed ½ inch thick to bring the road back to profile grade. The second lift of asphalt placed was a type “C” that was 1 ¼“. Some 21 years later in 1990 a contract level course was placed. That was a one inch layer. That is the last time anything was done to Route 6 in this area.

Right now I know some of you that have lived in the area, are crying foul, and I understand. There is a section from route “J” east through Altamont that had extra work performed in 1968 and a Contract Level Course (CLC) in 1986 with some shoulder up grade and another CLC in 2000.

My goal here is to share with you what MoDOT has done over the last 83 years on most of this section of road. I wish I could share with you what was spent in 1927 and each time there were improvements performed just so we could see what inflation has cost the taxpayers.

If there are some of you out there that have pictures from that time period, I would love to see them.

I will share this with you. The cost to the taxpayers of the two jobs now being done west of Gallatin on Route 6 and 69 is $2,281,387.

No concrete work

Order of work and as close a time line as possible, there will be no concrete repair work on this job due to the fact that they cannot dowel into the existing concrete. Both the age and the existing concrete being only six inches thick makes it impractical.

For concrete repair to work both sides of the patch have to be doweled into the existing concrete to make it stable. Otherwise when trucks and semi’s cross the patch they create a rocking motion and when water gets under the patch you have a pumping action that accelerates failure of the patch.

The long and the short of it, concrete repair is very expensive. Our tax dollars will be better spent rehabilitating the surface of the road.

Work started Aug. 24, with various lane closures set up in specific locations to stabilize shoulders with over-sized rock. This work was completed the next day, Aug. 25. The milling operation started Aug. 26, at the east end of the operation at the junction of Route 69 and Hwy. 6 in the eastbound lane.

Milling is big business

The contractor was to mill 1.5 inches deep into the existing asphalt. This had to be adjusted to 2.5 inches due to the underlying layer of asphalt not being stable enough to support the new two inches of asphalt. Asphalt millings from the job will be hauled to the APAC’s quarry off route 6.

This technique has become big business, the millings are high dollar. The main reason is the existing asphalt cement in the asphalt is an oil by product. The contractor will design a mix that takes into account the percent of AC (asphalt cement) from the millings. They will add virgin AC and aggregate and produce a mix that meets all the requirements set by MoDOT.

The milling operations are performed for several reasons. First, the road is in poor condition. By milling the contractor can reestablish the profile grade of the road. Second, this will help with the construction of the new four foot shoulders on each side as it will help hold down the cost of dirt work. Third, MoDOT forces have had to perform maintenance on this section of road for the last 20 years.

During that process they have had to use different types of asphalts (cold and hot), crack sealants. Nobody knows better than the contractor and field inspectors the adverse effects this has on Superpave mixes. Milling alleviates the problems.

Shortly after the milling operations the paving operations will start and the first lift Superpave 190 mix will be placed. There are 9,931 tons of the planned quantity of asphalt. That’s for one lift. And SP 125 will be 9,072 tons for the next lift.

Route 69 west of Altamont

Route 69 west of Altamont, MoDOT will resurface with Superpave; built type A3 (four foot) shoulder from Route I-35 to interchange to Route 6, through the City of Winston. The total length of the improvement being 4.291 miles.

Route B Daviess County: Thin-lift overlay (1 inch contract level course) from Rte I-35 to east to Rte 190. The total length of the improvement being 17.25 miles. That’s another 13,227 tons of asphalt.

Route 6 East of Gallatin will get a coldmill and resurface with Superpave from east of Route 13 to west of Route V between Jamesport and Gallatin. The total length of the improvement being 2.498 miles.NOTE:

The millings from this job and the job east of Gallatin will be screened and incorporated back into the mix called RAP (Recycled Asphalt Pavement).

And thus completes the work on Hwy. 69 and Route 6.

To eliminate confusion to the traveling public the two jobs run concurrently for eleven miles. We will work three more days on the westbound lanes, weather permitting. Then we will go east where it will take three or four days to complete the work. Then we will return to the west job and be there for about 30 days in order to widen the shoulders and put on the top lift.

Safety is paramount. If you are westbound, there will be delays; there’s no way around it. If you know you are traveling from 6:30 a.m. until 8 p.m., if you can find an alternate route to run, please do.

And remember if you are coming from a side road and you see a sign that says wait on the pilot car, then be sure and wait for the pilot car. That will help with safety a great deal.

If you have any questions, call Carl at 816-632-7304.

A guide to “highway” terminology

The “division 400 flexible pavements” section in the Missouri Standard and Specification for Highway Construction" is 63 pages long. Do you speak engineer? Probably not. And just like in the legal and medical manuals, if you don’t speak their language it can be hard to understand what they are talking about.Terminology can be hard to follow. I will start with the term “Superpave.

”“Superpave” is an overarching term for the results of the asphalt research portion of the 1987 – 1993 Strategic Highway Research Program (SHRP). Superpave consists of (1) an asphalt binder specification, (2) an HMA mix design method and (3) HMA tests and performance prediction models. Each one of these components is referred to by the term “Superpave.”

“Asphalt.” This area consists of research to develop a completely new approach to Hot Mix Asphalt (HMA) mix design. This has to do with the oil content, rock content and density requirements. All of these are pay factors for the contractor. It all needs to come into line and meet standard specifications for 100% pay.

“Pavement performance.” This area consists of the [Long Term Pavement Performance Program (LTPP)], a 20-year study of over 2,000 test sections of in-service U.S. and Canadian pavements to improve guidelines for building and maintaining pavements.