Salt On Calgary Roads?

[gustuphson]

Didn't the city decide recently that salt was a good idea and start using it on the roads?

 

http://www.theglobeandmail.com/news/techno...article1490631/

 

 

[daxlarsen]

Didn't the city decide recently that salt was a good idea and start using it on the roads?

 

http://www.theglobeandmail.com/news/techno...article1490631/

 

 

I'm not 100% sure but I think calgary refrains from using salt as it gets to cold here for it to be effective, I'm pretty sure that's why we use gravel for traction instead of salt to melt the snow.

[Heimdallr]

I always thought that Calgary didn't use salt. The idea that they don't because it's too cold for it to be effective doesn't make sense though because they use it up north where it is colder on average.

[Taco]

30,000 to 40,000t/yr Here

[reevesr1]

Calgary uses Calcium Chloride. There is a spreadsheet on this site which goes over the pros and cons

 

Salts

[jack]

When I was in Calgary for the FF Expo, the City was using a de-icing pretreatment similar to what some cities in BC do. Applied in liquid form it is more effective than straight salt(works to -15C) and contains anti-corrosion components.

j

[beedhead]

30,000 to 40,000t/yr Here

 

Too funny!!!...Lol..

[Taco]

Sorry Angus,

[chiasson]

What gets me is that they don't plow many of the secondary roads after it snows in Calgary. I've lived in the NW for three years and many of the streets turn into sheets of glass from packed down snow. It's sometimes like this for days. Where I'm from out east every single road gets plowed every time it snows.

[gustuphson]

so helpful Taco, soooo helpful

search google

[Taco]

Thank you, I'll be here all week...................................

 

 

 

 

[Pipestoneflyguy]

Calcium Chloride is just one tool - it can lower the effective temperature, but effectiveness at -15 is rare and difficult to acheive, other factors such as prevailing weather, traffic volume, surface and air temps, humidity play a key roles in that decision - using Calcium as a deicing agent really has two functional applications, one being to prevent black ice formation in anticipation of an appropriate dew point and humidity level and the other as a tool to reduce adhesion and hardpack formation in anticipation of an oncoming weather system. This particular chloride has a tendency to create slime if used in too rich of a concentration or heavy application so it is somewhat of a higher maintenence system

 

Magnesium chloride is used as a pre-wetting agent and ani-icer, applying it to abraisive or rock salt (usually via a nozzle sprayer at distribution) can be used to improve abraisive adhesion to hard pack surfaces (on a pavement surface, the first tractor trailer to pass at 110kmph will remove 80%-90% of the applied abraisive, mag also helps reduce this effect by working as a bonding agent) Mag chloride can also be used as a solium chloride (fine to coarse crushed) accelerant, for example, to aggressevily disolve an existing hard pack layer. also works great as a response to unforecast black ice formations or battle shade or humidity effect (rock cuts and roads close to water bodies or flows) - when you travel the TCH through the Parks if you see the little diamond reflectors on c-channel in the ditches, they are the stop and start indicators for application of mag chloride as an inti-acing agent aligned with high humidity locations.

 

In general salt only works as a de-icer or anti icer when in the form of a brine, this is true for all chlorides and why the effective temperature range of liquids is broader - the trade off is that quick response does result in less duration or a need for greater frequency in application - the nature of the liquid is that it somewhat quickly washes itself off the road surface, so not only is the unit cost much higher than base sodium the usage need is greater - really it is best used as a quick response tool or as a premptive tool for black ice - the city of Hamilton actually has computer controlled automatic sprayers mounted on some of their troublesome bridges.

 

Rock salt coupled with a solid understanding of capabilities and environmental factors can be the most cost effective tool, as long as it exists as an economically feasible resourse, it will remain the primary tool despite its effectiveness range varying between -7 and -10 on its own - air temperature is a contributory factor, surface ground temp is the difining factor in the decision process. I think most folks would be a little surprised if they new how much and how often salt is used, even in the park - If you have driven the parkway between Lake Louise and Jasper and noticed how rough and thick the icepack often gets, well as a comparison this is what you would see on much of the TCH without the use of chlorides.

 

I can't speak to the effective of chlorides in high concentrations in places like toronto for example but here in the mountains the envoronmental effect is negligible - I authored the EAP for use of magnesium chlorides in this Natioanl Parks and the measurable impact seemed to be limited to a slight wiltering effect on roadside growth - the primary concerns are animals and birds being struck by vehicles while consuming salt residues off road surfaces, luckily spring rains generaly relieve that particular issue and also dilute levels to barely measurable beyond a few metres from the road. The largest environmental considerations are oriented around storage and optimization of usage.

 

The decision to plow and maintain secondary roads is purely economic - methods and standards are as varied in the east as they are here - try driving around Montreal or Quebec city on a typical snow year, many side roads in these cities make Calgary's road conditions seem like a cake walk comparitively - most cities in Ontario remove snow from secondaries as local citizens demand and pay for the service through municipal taxes.

 

Anyway consider this just a glimpse of the baseline information relevent to use of chlorides hopefully interesting to someone other than me LOL.

 

 

 

 

 

 

[ÜberFly]

Wow Rob!

 

Quite comprehensive!!

 

Thanks!

 

P

[Teck71]

What gets me is that they don't plow many of the secondary roads after it snows in Calgary. I've lived in the NW for three years and many of the streets turn into sheets of glass from packed down snow. It's sometimes like this for days. Where I'm from out east every single road gets plowed every time it snows.

 

Yeah Back in Kingston ON if you park on the street after Nov. 1st you get towed. the tow trucks will actually follow the plow if need be.

 

Every street gets plowed.