expansion joint vs continuity slab

[kafo]

My design for a 15m-28.8m-13m-28.8m-15m spans bridge was based on using RC precast girders for 15 and 13 m spans while prestressed precast Girders are used for the 28.8 span. I separated all spans with expansion joints. I think this is better to separate RC from prestressed girders due to different creep and shrinkage. Now the reviewer objects and ask me to redesign using continuity slab all over the bridge "jointless". How can i defend my theory and can you support me with a reference on the topic that can help me defend my design against the reviewer comments? Thanks!

 

[wiktor]

I think that the case is lost anyway.
To design in current days simple supported spans is unacceptable.
There will be slight difference in the creep in between RC and prestress, but that's a small issue.
To have a bridge with a joint at every span it's a maintenance nightmare.

 

[MichSt]

I agree with eliminating the deck joints due to future maintenance issues. That's pretty much standard practice now where practable, as mentioned above.

If you're concerned with movement issues between your beam types, why not make all the spans prestressed??? What's the point of mixing your beam types?

For a "jointless" bridge deck configuration I would still design the beams as simply supported for bending moment. The deck would then be reinforced and designed for the negative moments at your piers.