Concrete debonding
Concrete debonding
(OP)
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
Thanks to all in advance





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