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The picture below shows a veritcal construction joint of an approximately 50 years old reinforced concrete industrial structure. The expansion joint was likely originally sealed with a flexcell which due to age and water ingress has deterioriated and come away from the joint exposing a peforated metal pipe.

My question is does any one know why the pefortated pipe was installed there originally approximately 50 years ago? Does it have a drainage purpose? The joint should have been waterstopped. Is this a second line of defence? If so where do you expect it to drain to? Has anyone seen a similar detail to this before?

perforated pipe within construction joint

egg
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1 Answers1

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Yes, it is a hydrostatic pressure relief pipe (part of the drainage).

Behind all the retaining walls, swales, subdivision's low land lots, you need to have a trench or channel filled with aggregate and a perforated pipe leading to surface runoff drainage as a minimum.

The Aggregate mus be stratified from 1.5" near the pipe to sand 18" out.

I suspect in your photo corrosion has washed the aggregate out.

kamran
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