Windsor’s Prestressed Systems builds Ontario’s first NU girders

For the first time in Ontario, a company is building NU girders, developed at University of Nebraska and which up to now have been used only in limited projects in western Canada.

Prestressed Systems Inc. (PSI) invested in the steel forms and stressing and detensioning equipment, to make and cure the larger profile and elongated girders as part of an almost $20 million contract with the Windsor Essex Mobility Group, the consortium building the $1.4 billion, 11-km Windsor-Essex Parkway, the mostly submerged six-lane highway that will extend Hwy. 401 to a new bridge linking Windsor and Detroit.

Prestressed received a contract for 546 girders as well as for more than 12,000 precast deck slabs for bridges and tunnels along the route. It has already installed several girders on the rebuilt North Talbot Rd. bridge, which opened in August, over a widened six lane existing Hwy. 401 less than a kilometre from where the Parkway starts.

Prestressed is a 37-year-old company with plants in Windsor and River Rouge, Mich., and has had extensive experience in all forms of structural products from bridge girders to hollow core floor slabs to exterior panels, stadium seating, architectural precast, and noise barriers.

NU girders are I girders with a wider cross section allowing for fewer girders than standard CPCI girders. They’re also longer because the bottom flange can incorporate more steel strands.

In the case of the Parkway project each girder measures 85 ft. and has 44 strands, which are pulled then released after a day of curing. Curing takes four days in the summer and up to seven in winter. The girders’ heights vary from 1.4 to 1.9 metres. They include polypropylene fibres for fire prevention.

“A NU girder will withstand more load so you can space it further apart than the CPCI standard girder so therefore you’re eliminating a few girders,” Prestressed Parkway project manager Maurice Adoranti said.

Each strand is pulled to almost 40,000 pounds, resulting in almost 180,000 pounds of force per girder. The elongated girders were chosen by the consortium, which is building the highway for the Ontario government, for their value in a large scale project like this.

Prestressed’s contract is divided into $11 million for the girders and more than $7 million for the slabs.

Prestressed’s contract is for one-third of the Parkway’s 1,500 girders. Another company affiliated with the Spanish-led consortium is constructing additional girders near the Detroit River in industrial west Windsor.

The large girders require 400 and 600 tonne cranes, some of the biggest in Ontario, which are based in the GTA.

The contract will take 14 months, require more than 100,000 man hours including girder installation. The firm hired an additional 15 – 20 staff.

Loris Collavino said his company is pleased to have won the contract and introduce the new girder to the province.

“Everyone within our organization is very happy to know that we’re contributing to the local economy and we’ll leave our mark on the project for years to come,” he said.

But he said negotiations were difficult to win it.

“The contract was a very big and cumbersome contract, a lot of stipulations, a lot of qualifications,” Collavino said. “It took us many months to review that contract and make changes that we could live with and also that the contractor could live with.”

Garfield Dales, MTO’s Parkway project delivery manager, said the ministry is “very excited” that NU girders are first being installed on the Parkway.

“Because of the size and the scale of this project, it was really something that the consortium looked at in terms of bringing innovation to us,” he said.

Dales said the potential to use NU girders on other large scale projects “is there.”

The MTO media tour at PSI’s yard also made a point of listing numerous local firms that have obtained work on the Parkway. Since work began in 2011, 98 per cent of subcontracts have gone to area firms.

The Windsor Construction Association in August criticized the difficulty obtaining work for Windsor-based companies.