Composite structure for bridges 1

[yarsky]

Steel-concrete (including lightweight concrete) composite structures are well known in building construction (static loading mostly). Could somebody share information/opinion of such structures subject to dynamic loading (bridges)?
May lightweight concrete be used as concrete component in composite structures for bridge spans?
Thanks.

 

[Qshake]

Lightweight concrete is, indeed, used in certain bridge applications but not on a widespread basis in the industry.

While I suspect there are many factors influencing this decision, what comes up most is durability and resilience in service life. Most DOTs prefer to design using something that will have a low maintenance cost rather than low initial costs.

However, when looking for ways to increase load capacity lightweight concrete is often used.

Regards,
Qshake

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[LittleWheels]

I know of three nearby bridges built using lightweight concrete, albeit as reinforced concrete, not composite. All have significant concrete deterioration after about 30 years in service. I wouldn't build a new bridge using lightweight concrete structurally.

 

[blake989]

Currently in my area, the price difference for lightweight concrete will FAR exceed the savings you may save in steel weight. Start checking with your local suppliers about price before you go any further with this thought.