According to the news storm is coming!

[XJ]

Huh, as a muggle I assumed that plows had a simple consumable edge like HDPE.

Had no idea that there was a lot of complexity to running a plow, but in hindsight, it makes sense.

Any additional education would be great.

[theGinsue]

Depends on the pavement material and condition. On Vail pass the plows remove 1-2 inches of asphalt per year. Mainly from the blades shaving the peaks of the ruts from truck tire chains. We are trying 3 concrete test sections to see if tire chain rutting can be mitigated. Monitoring the wear of the test sections and new asphalt placed last year.

Asphalt that is cracked is very vulnerable to freeze thaw damage causing layer delamination and chucking of the pavement.

On concrete blades can chip away the corners of the panels as they curl up from temperature diferential.

Most concrete placed in the last 40 years is air entrained to mitigate freezing damage. Most damage you see at joints is from the de-icer. The chloride reacts with the concrete and forms an expansive gel the beaks apart the concrete. This is mitigated with coal fly ash, slag or other pozzolanic materials. Cdot pavement for the past 20+ years has mitigated this reaction. Local roads, especially El Paso County concrete roads do not contain the required pozzolan for mitigation. This county is run by the developers who do not want to use it since it slows down strength gain a few days. These idiots running El Paso County are saving a few days today for expensive early age deterioration repairs and traffic delays.

The cost of blades is minimal compared to the cost of pavement.

Awesome response; thank you. I definitely appreciate the more technical info that helped me understand things I've noticed and suspected.

As to the cost of blades being less than pavement, my guess is that there is a separate budget for snow removal supplies and equipment which is probably far too low so they stretch the dollars by preserving the blades - which creates hazardous driving conditions.

Most municipalities have shoes or bogey wheels on their plows, they usually are about 1/8" above the pavement.
DOT plows are on the pavement, we had replaceable blades with a carbide insert. In a storm event such as this one it would not be unusual to go through a couple sets of blades.
Good times being squatted under a frozen plow @ 0200 dripping slush down your neck wrestling 125#, 6' long and 3/4" thick blades fishing 5/8" diameter bolts to hold them without them slipping out of your hand.

I've paid close attention to many plows on Colo Spr trucks and never noticed any shoes holding the blades up but I've clearly seen the blades raised a couple of inches about the pavement. About 10 yrs ago I asked a city plow driver about it and was told it was to reduce wear on the blades. But like StagLefty said, it packs the remaining snow down which is then turned to a nice gloss when the sun hits it. Wonder skating rink effect. I can't tell you the last time I saw a plow blade create sparks which is something I saw regularly growing up and in Massachusetts.

On top of this, the witch who was in charge of Colo Spr street planning until a couple of years ago started having all of the lanes narrower "to reduce speeding". Now you've got cars close in with drivers who won't get more than a few feet off of your bumper and once the snow falls the city turns into one big bumper car arena.

ETA: For the record, I have mad respect for the plow operators and what they do. I just wish the bureaucrats giving the directions appreciated the citizens equally as much.

[Eric P]

Eric P, very interesting information about surface wear factors but not surprising. For some time I worked heavy and highway and operated concrete plants for many years. In the early 70's, air entrainment was an extra cost additive and many contractors didn't buy it. A few years later it became industry standard and a required part of the mix package. The early fly ash mixes flowed nicely but didn't hold up very well. I wonder if steel pellets mixed with concrete might be cost effective? I don't know about current practices but it was used for heavy traffic warehouse floors.

I notice a lot of roadside tree loss from mag chloride but haven't seen an effort to remove the dead trees. I would guess that failed catalytic converters probably start a majority of highway fires and I expect the problem will get worse in the next few years.

Early fly ash had poor controls and high in carbon. The carbon absorbed the air entrainment admixture turning the mix into a no air mix. Steel will rust and expand, breaking the concrete apart from the inside.

We are trying 3 types of concrete on vail pass. A standard pavement mix, one with lots of silica fume a d the 3rd with carbon nano tubes. Silica fume is used in concrete for energy dispersion blocks on dam spillway since if helps resist the abrasion from the water and aggregate particles. The nano tubes are new to concrete. They were used in concrete pads for snow cats at vail resorts. The snowcats have carbide tracks and vail resorts has gone 4 seasons without needing to replace the pads. The pads are usually replaced every 2-4 years from wear.

I jokingly told the resident engineer and maintainance super that I want my name to be cursed when blades snag on these panels as the asphalt wears away and they forget to lift the blade. If these work at resisting wear, when they add the climbing lanes they would use voncrete for the truck lanes.