Stainless integral to bridge's 300 year design life

Stainless integral to bridge's 300 year design life

Queensland’s largest ever road and bridge project will rely, in part, on innovation within the stainless steel industry to meet its design life of 300 years.

The Gateway Upgrade Project in Brisbane, which includes construction of a second Gateway Bridge and is being delivered by Queensland Motorways with design, construction and maintenance by the Leighton Abigroup Joint Venture (LAJV), will use reinforcement bar made for the first time from Outokumpu Group’s LDX 2101® duplex stainless steel.

A total of 130 tonnes of duplex stainless steel will be used in the bridge’s most critical structures: the splash zones of the two main river piers (28 tonnes of LDX 2101® have already been supplied and some Duplex 2205 will be used due to availability of dimensions for certain components).

Gateway Bridge Alliance Manager Gerry van der Wal said LDX2101® was chosen due to its high level of corrosion resistance (close to 316L) and low nickel content, which made it more cost effective and less susceptible to rapidly escalating worldwide nickel prices.

Outokumpu’s Qld and NT Manager Ken Hayes said that in bridge construction, stainless steel should be specified for parts where it makes a positive contribution, such as splash zones and the bridge deck.bridgepillar

“If carbon steel rebar is used, the bridge deck needs a water-proof membrane and the concrete must be of high quality, whereas if stainless rebar is used, reduced concrete cover can be specified, and it is also possible to relax the design criteria with respect to maximum crack width,” he said.

“As a result, with stainless rebar, bridges can be built either with no extra cost or for a lower cost than by using carbon steel reinforcement.”

Mr Hayes said LDX2101® offered the most cost-effective alternative for durable reinforced concrete structures and, due to its good price stability, it offered construction projects vitally important predictability.

“The win-win outcome from the use of LDX2101® is much improved sustainability in our constructed environment,” he said.

Because LDX2101® had never been used for rebar before this project, Outokumpu’s metallurgists carried out extensive tests to ensure it would withstand a high corrosion environment if the concrete were permeated by seawater.

A trial rebar coil was also sent to Atlas Specialty Metals’ Durinox facility in Melbourne to ensure it could be easily straightened.

Durinox Manager Colin McGill said they had to decoil the material, cut it to length and bend it to the appropriate shape.

“This was the first time we had processed the material and there were some challenges we had to overcome because of its very high strength,” Mr McGill said.

Once Outokumpu’s quality system and external testing criteria were approved by LAJV, the initial 28 tonnes of the hot rolled, ribbed, 16mm LDX2101® were delivered to Atlas Specialty Metals in Melbourne in 750kg coils for processing between October and December 2007.

The $1.88 billion Gateway Upgrade Project will be completed in 2011. It includes duplication of the original Gateway Bridge (which was completed in 1986), upgrade to 12km of the Gateway Motorway and construction of a new 7km deviation providing better access to Brisbane Airport.

Just over 20 years after it was constructed, the original Gateway Bridge is now exceeding capacity, carrying more than 100,000 vehicles each day.

When the duplication project is complete, the original bridge will carry six lanes of traffic north and the new bridge will carry six lanes of traffic south.

The new bridge is a 1.6km long balanced cantilever motorway bridge with the main span measuring 260 metres.

This article featured in Australian Stainless Issue 42 - Summer 2008.

Photos courtesy of Leighton Abigroup Joint Venture.

ASSDA - Supporting You

ASSDA’s activities focus on networking, promotion, education, accreditation, standards development and problem-solving. View the Association's history of achievements and milestones in supporting the Australian stainless steel industry here.

160+

Member Organisations

100+

Publications

8,775+

Stainless Steel Specialist
Course enrolments

Check out our services

 

Stainless Steel Specialist Course

An online educational tool designed to improve your knowledge of stainless steel, its properties, performance and uses. Consisting of 17 challenging and rewarding modules, the course delivers a standard level of knowledge and qualification across the industry.

Learn more
 

ASSDA webinars

ASSDA's webinar program was introduced in late 2014, providing educational presentations on various stainless steel topics for Members, the specifying community and the stainless steel industry as a whole.

Learn more
 

Technical inquiries

ASSDA's Technical Support Service represents a significant asset to the local stainless steel industry, providing excellent and timely advice for the successful use of the product.

Learn more
 

ASSDA resources

ASSDA delivers a strong publications and training program with a range of titles available to participants in the stainless steel industry.

Learn more

Stainless Steel Industry Directory

As the go-to resource for the stainless steel industry in Australia, this directory is designed to showcase the capabilities of ASSDA Members and Accredited Fabricators while also serving as a platform to connect businesses with potential work opportunities.
Whether you’re a professional within the industry or a client seeking a specific stainless steel service, the Stainless Steel Industry Directory is here to facilitate connections and collaborations. Browse ASSDA’s Directory now to discover the businesses and services that can meet your stainless steel needs effectively and efficiently.

ASSDA Young Professionals Network

Empowering the next generation of stainless steel professionals and leaders.