© Geraldine Brophy
City of Corner Brook's director of operational services Steve May, left, addresses city council on paving that will be done this year during the Monday, June 23, 2014 public council meeting.
The City of Corner Brook is hoping the asphalt mix it plans to use this year will have a greater longevity than that of previous years.
The city plans to lay roughly 11,000 tonnes of asphalt this year and as part of the paving program council approved a contract with AMEC for inspection and testing services of that pavement during its public meeting on Monday. The contract is valued at $99,119.
Following the meeting Steve May, director of operational services, said past paving programs were carried out with a design of the asphalt mix and then inspection of the asphalt.
“This time around we’re going to minimize the design and just go with the provincial design,” said May. It will be the same mix that’s used on the province’s highways.
May said explaining the differences between the two mixes is complicated.
“Over the years we have had different viewpoints,” he said.
Using the asphalt content, the liquid content, of pavement as an example, May said at one point the city moved to the lower side, while the province was on the higher side.
“The recent couple of designs we’ve done, we seem to have gone towards the middle,” he said.
He said there are a host of details associated with developing a mix that includes anti-stripping components, the percentage of fines and is the aggregate washed or not washed.
“We wish it was simpler, but it’s not,” May said.
But he’s hopeful going with the provincial mix will result in pavement that stands up for longer.
Lifespan of asphalt
“When you attend an asphalt conference or you speak to the asphalt industry specialists, 20 years is reasonable,” said May of how long pavement should last.
But he said that’s impacted by many things, including traffic volume, the loading a road sees, the number of freeze-thaw cycles, tires and traffic paths.
“All these factors lead to decreasing the life of an asphalt surface,” said May.
“I don’t know if there’s a more challengeing environment than we have here in Corner Brook,” he added. “We have significant grades on a lot of our roads, so that adds wear and tear from the tires.”
May also said there is a large number of studded tires used around the city and without studying how much of an impact they have on roads he’s confident that “studs don’t improve asphalt.”
May said Marine Contractors should get a start on the paving around the city this week. They’ll start on the side roads where testing will be conducted to make sure things are going well before moving to the main roads.
He said the vast majority of paving will involve significant sections of roads.
“We have a large number of patches to do because of all the water and sewer breaks.”
Those patches have increased in size because of regulations on trenching requirements.
May said a typical water and sewer cut that used to be six feet wide is now potentially 15 to 20 feet wide depending on the depth of the dig.
The paving that has already occurred on O’Connell Drive is part of the previous year’s program, but May noted the contractor is working off the current specifications.