Canadian ‘Blackspot’ gets upgrade with new Dynapac rollers

New Dynapac compaction rollers have recently been delivered to Canadian contractors InterCite Construction and Pavex of St Felicien, for work on upgrading Route 175 – one of Canada’s most dangerous highways, in the Province of Quebec – it includes a Dynapac CP224 pneumatic rubber tired roller and a CC524HF double drum vibratory roller.

Route 175
Route 175 is a key 174km long highway through Canada’s Parc des Laurentides National Park – an area of outstanding beauty – and linking Quebec City and the northern city of Saguenay ( Chicoutimi ). The highway is widely used by loggers, transporters, regional and tourist traffic.

It is also considered to be one of the country’s most dangerous highways being subject to frequent poor weather conditions. Accidents caused by moose on the highway are also not uncommon.

Originally a single lane in each direction, the highway had progressively been partially built to autoroute standards but with many sections still single lane or with an overtaking third lane.

It nevertheless remains an accident black spot.

Following lengthy negotiations between the Quebec and Federal Governments funding of almost $637 million to upgrade the highway was confirmed in 2002 by Prime Minister Jean Chretien and Premier Bernard Landry.

By 2005 work was started on upgrading to a four lane, dual carriageway along the full length of the highway with a completion date of 2012.

With the first four-lane section completed in 2007, some 67km had been completed by 2008 with a further 16km in 2009.

Experimental specs
Highway engineers, in seeking ways to extend the asphalt lifespan throughout Canada’s harsh winters, where snowfall can be up to 3m deep and a frost penetration of more than a metre can be experienced, are experimenting with different asphalt thickness’s, layers and compaction densities.

Additional asphalt damage is also caused by the country’s unregulated lorry load axle weights.

The highway is being generally built with at least a metre high embankment to reduce frost penetration. Highway engineers have also specified low mix asphalt and low compaction density to absorb any soil/asphalt movement together with a bottom, third anti-cracking asphalt layer – particularly along Intercite’s segment at km154.

Together, it is anticipated that these will offer flexibility in the pavement to prevent possible cracking during the harsh winter months.

Compaction duties
Contracts are generally broken down into 5-10 km segments with the two contractors- Pavex of St Felecien and Intercite Construction working at km143 and km154 respectively – recently taking delivery of new purpose-ordered Dynapac compaction equipment for the brief summer month’s construction ‘window’.

Intercite Construction is currently working on a 10km segment from km154 and has, since 2005, completed almost 70km of highway along Route 175 close to Chicoutimi with a large fleet of Dynapac rollers.

For its latest contract, Inter Cite is laying a specified 55–66 mm thick ESG5 asphalt mix, featuring a 0.5mm aggregate mixed with sand and bitumen, as an anti-cracking (fissure) layer.

This is topped by an ESG14 mix to depths of between 68–80 mm as specified with a 50 mm top ESG10 wearing coarse. All the asphalt layers are compacted to meet a minimum of 93% compaction density and a maximum of 98% depending of the section of road.

Joining a Dynapac CP221 roller, Intercite took delivery in July from local dealer J A Larue Inc. the first CP224 with an air conditioned cab in the country.

The 21t class roller features seven rubber tyred wheels and offers, according to operator Olivier Bouchard, “a great ride”.

“The operator’s seat is so much more comfortable than previous models and the air conditioned cab is a real bonus in the summer months”, he said.

“I can also adjust the water sprinklers which will be particularly important during, for example, the fall ensuring less water is used to maintain a higher temperature on the tyres” he enthused.

Km143
Pavex of St Felicien, for its segment at km143, took delivery from J A Larue Inc. a new Dynapac CC524HF in May to complete a Dynapac compaction train comprising a CC522HF compaction roller and a rubber tyred CP221.

Utilising the CC522HF with four passes behind the paver, the CP221 roller follows with one or two passes to seal the asphalt.

The new CC524HF double drum compaction roller completes the cycle with a single vibratory pass over the 500m pass length for the first asphalt layer. For the top layer the roller provides a static mode pass.

The 12.7t class CC524HF tandem roller features a drum width of 1950mm and offers a high/low frequency amplitude of 51/67 Hz.

It is powered by a Cummins QSB 4-5 T3 water-cooled, turbo-diesel engine with an after cooler and is rated at 93 kW (125 hp) at 2200 rpm.

For further details please contact:

Lotta Bynke, Dynapac AB
 lotta.bynke@se.atlascopco.com

Dynapac is part of the Atlas Copco Group within the Atlas Copco Road Construction Equipment division. We are experts on asphalt, soil and concrete applications, committed to customer performance worldwide. Products and solutions are marketed under the Dynapac brand and complementary brands. Headquartered in Stockholm, Sweden, the division has production facilities in Europe, USA, South America and Asia.