An evolution in long span girders

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Improved form of long span precast beam for use in bridges – A need was identified for a girder that could span beyond the 32-35m limit of ‘standard’ precast girders on the east coast of Australia.

Developed by Quickcell Technology Products of Australia

Technical support by Arup Brisbane

Proof checked by Parsons Brinckerhoff

Now approved through a rigorous design development and approval process with Queensland Department of Main Roads, including the manufacture and testing of a prototype girder.

Other Main Roads Authorities in other states in Australia now going through acceptance of girder

Interested in product to market opportunities in USA

Quickcell Super Girder

4 Quickcell Super Girder

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No need for deck falsework – immediate working platform

Long spans – narrower flanges (decrease in structure height 31m to 35m range, ie similar depth girder can span longer)

wide beam spacing – reduces the number of girders in each span

Simple precasting – in standard moulds

Intermediate stiffeners can support services & better resist accidental collisions

No in-situ or steel cross diaphragms except at girder ends

Girders can be have second stage post-tensioning inserted to enable continuity for example.

The width of the flanges mean that large differences in width and tight horizontal curves can be accommodated in the flange on the outer girders.

Quickcell Super Girder

6 Quickcell Super Girder

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QR Std 25m Span Deck Cross-section QR Std 1600mm deep girder

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10 Quickcell Super Girder

150’ (45m) span with 6’-6” deep beams at 8’-0” spacing

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Bulb Deck Tee – WSDOT and Oregon (deflected strands)

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13 Quickcell Super Girder

Can span longer than 50m if use two stage prestressing. (Although current TMR approval is only for single stage prestressing upto 46m.)

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• number of girders can be reduced for a typical 25m I-girder span.• example:

single track – 2 Quickcell girders to three QR girders typically (Refer below)

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The girders provide an easier and safer manufacturing with no closed voids

Based on a 24 hour production cycle, the number of girders for a typical bridge can be cast much quicker which leads to a lower cost, as there are typically less girders per span

Safety – Casting second stage parapet upstand for deck construction

Overall reduction in weight to possible reduction in substructure. ie total superstructure dead weight less than similar T-roff girder superstructure

Less girders means less transportation costs (even if slightly heavier)

Overall reduction in number of girders can lead to upto 30% savings on supply of girders.

Quickcell Super Girder

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• Less girders requires less maintenance

• More robust element – ie webs are thicker which helps with durability,

especially with more onerous environmental classifications.

• In developing this girder, the details such as diaphragms, bearings, etc

have been kept the same as the supertee, as this is what industry

knows. No education required on construction side.

• The removal of enclosed voids removes potential durability issues

with entrapped moisture.

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The wider flange width (up to 3400mm) may create challenges with transportation, however this is within the maximum transportation width.

Deck has lower transverse distribution of live load than a Super-T that has greater torsional stiffness; however this is accounted for in the greater flexural stiffness longitudinally.

Stability under transport and construction for the narrow longer beams is not considered to be an issue because of the transverse stiffness, with the top flange and support of the intermediate stiffeners.

Transport of uneven loads carried out as currently done. For instance, the use of anchor holes and chains is commonplace to support such loads..

Manufacture of Prototype Girder

MouldHydraulics