February 26, 2010

MTO

Zoom with a view: the MTO is employing transparent noise barriers on highway projects.

FEATURE | Roadbuilding

Transparent noise barrier pilot program launched on QEW

PETER KENTER

correspondent

Monolithic noise barriers have become a regular feature of Ontario highway construction. Now a pilot program by the Ministry of Transportation (MTO) has thrown a little light on the subject by specifying transparent barrier materials along sections of the Queen Elizabeth Way (QEW) through St. Catharines and Fort Erie.

“The transparent barriers let in more light, provide commercial visibility for businesses and reduce the visual intrusiveness of the barriers for drivers,” says Chris Blaney, Senior Environmental Planner-Acoustics with MTO’s Planning and Environmental Office.

The product, known as Paraglas Soundstop, is supplied by Armtech Durisol in Hamilton, and came to Blaney’s attention after it was successfully employed on an Alaskan road project. The transparent element is constructed of a sound-reflective composite plastic material imported from the U.S., then assembled at the company’s facility in Mitchell, ON. The surface of the material is so smooth that dirt won’t stick to it, ensuring that the product is essentially maintenance-free. The lightweight panels are stacked between the steel ‘H’ posts that support noise barriers, just like traditional panels.

“There’s little or no difference for the contractors who install it,” says Blaney. “The panels are delivered by truck, lifted by crane and inserted between the “H” posts with no additional field labour required.”

The transparent barrier contains an imbedded polycarbonate filament and a cable bolted through the glazing, which is tack welded to the “H” posts. “Even if the barrier is struck by a truck, there would be minimal danger from falling debris to pedestrians walking underneath,” says Blaney. “All of the major elements of the barrier will be kept together.”

The transparent barrier product was approved by the province for use on MTO contracts and installed in a demo project in Fort Erie in 2005. The test span measured about 100 metres in length by three metres high and was subjected to weatherometer, freeze/thaw, anti-fracturing and ultraviolet tests. The pilot installation continues to perform according to spec into 2010.

The first full-fledged installation for the transparent barriers is the $167-million project to widen the QEW to six lanes through St. Catharines, awarded to Dufferin Construction. Sub-contractor Peninsula Construction Inc. of Thorold installed the project’s 26,000 square metres of highway barriers, including almost 3,000 square metres of transparent barriers extending from the city’s Henley Bridge to west of the Garden City Skyway.

“We worked the bugs out of the product in Fort Erie before we put it up in a big job,” says Blaney. “For the St. Catharines installation we used it at the top of the walls which can be as high as 12 metres. It softens the appearance of the structures and decreases the closed-in feeling of the highways.”

The transparent panels were staggered on either side of the road for both aesthetic and financial reasons.

Traditional noise barriers cost MTO roughly $450 per square metre, including installation.

“The premium on transparent barriers results in a total cost of about $750 per square metre, installed,” says Blaney. “We focused on places where the walls were really high on the residential side, but they were not installed in parallel. That way we could break up the monotony of the wall system.”

By the time the QEW expansion project began, Durisol had also developed a product that could be installed the entire height of the barrier on a bridge.

That product was also employed in the project. “Under normal circumstances that product would have cost us a little more, but Durisol did not charge us a premium for this contract,” says Blaney.

As of February, the QEW barrier project is about 95 per cent complete. MTO has further plans to use the transparent barriers on Kitchener’s Conestoga Parkway and along a two-kilometre section of Highways 401 and 3 in Windsor.

“Transparent noise barriers are now another regular option for our highway barrier construction program,” says Blaney.

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