SCAN 1

[dik]

From an ariticle in the Fall 2022, Aspire, Concrete Bridge magazine that might be of interest:

http://www.aspiremagazinebyengineers.com/?m=61068&i=761445&p=1&ver=html5

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[BridgeSmith]

I'll have to see if I can access that report. Settling approach slabs have definitely been one of the most persistent issues for bridge construction, particularly for integral abutment bridges.

Our standard now is to add a sleeper slab between the roadway and the approach slab, and move the expansion joint to between the sleeper slab and approach slab.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[bridgebuster]

Thanks dik.

In NY, we use a sleeper slab with semi-integral & integral abutments, & jointless bridges. For conventional abutments with deck joints the sleeper slab is omitted. On the bridge end the approach slab sits on a key in the backwall.

 

[IDS]

Link for the actual report (freely accessible):

https://onlinepubs.trb.org/Onlinepubs/nchrp/docs/SCAN19-01rev3.pdf

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[dik]

Thanks IDS...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[OSUCivlEng]

I'm curious what material(s) is used for backfill behind the abutment and under the approach slab in other states. Here we use controlled low strength material (CLSM) also known as flowable fill. We set the approach slab on top of the backwall so the settlement always occurs at the end of the approach slab.

On a recent project I used a double approach slab with a sleeper slab where the two slabs meet. I used the same design for 4 different bridges and I had one sleeper out of eight settle. It was very strange that the slab sunk directly over the sleeper slab and it was uniform across the roadway.