Concrete debonding 1

[gosai]

I have a job site where debonding of concrete occured on a concrete pier. The concrete was poured 7 months back. recently a big visible shear crack occured. Two photos are attached. I am not sure why this happen? Is any one can provide causes for debonding of the concrete and recommendation to fix it?
Thanks to all in advance

 

[Ron]

Only 1 photo shows up.

This looks like form laitance. This is caused by too much water trapped against the form, creating a plane of weak concrete at the surface that popped off. It also looks like the concrete contains GGBFS cement...which could indicate that the forms were pulled a bit too soon...before adequate strength gain of the concrete.

 

[JedClampett]

It's hard to tell, but the conduit (pipe) in the photo looks very close to the surface. Probably not the root cause, but sloppy none the less.

 

[Ron]

There is also a possibility that there was insufficient form release used on the form surfaces, thus the form stuck when removed, causing a tensile failure in the concrete surface that didn't show for a while. Hard to tell from photos.

The formed surfaces were not true and plumb and it looks like two different placements. Poor QC. Could be a variety of things that caused it.

First, get a local structural engineer to look at it to determine if there is a structural or cover issue. If there is, that has to be addressed first. If not, it is a cosmetic repair that can be done with a repair mortar.

 

[gosai]

Thanks for the reply,
Let me attached the first photo to show how the crack developed. One of the sub trade also noticed water dripping from the pipe conduit. The temperature was below 0 for some days and then in +.
Ron, the pier was poured up to underside of the base plate elevation. The separate layer is a base plate grout and on top the pier was pour after installing base plate. The exposed steel plate is a cap plate for tension transfer.

 

[hokie66]

Not sure what I am looking at. Where is this base plate and cap plate? What tension transfer? Perhaps you can give us a sketch or detail of how this was to be built.

If there was a void of some kind, filled with water which froze, that could easily explain the spalling.