Concrete Column - cold joint cracking 1

[NFExp]

I was informed that the column in the photo was poured in 2 pours with a cold joint in the middle portion of the column. The cold joint looks to me like it occurs right where the column is cracking. The column is for a two story high end residence and is oversized for the loads however it does support lateral wind loads and some MWFRS loads for the house.

It looks bad to me so my instincts are to tell the contractor to demo the column and repour the column and beam above.

Also to add to the issue, the contractor did not get a break test at the column. We are exploring getting a Schmidt hammer test to confirm the compressive strength of the concrete.

Please let me know your thoughts

 

[JAE]

Is it just one of the columns? Or several?
Looks like perhaps the column was bumped or deflected to cause a crack like that so soon after placement. Maybe when the forms were being removed?

It's just my view - but Schmidt hammer is worthless unless you have nearby, recent concrete elements where you've had proper cylinder tests done to calibrate it properly - and even then I wouldn't trust it.

 

[HTURKAK]

.........The cold joint looks to me like it occurs right where the column is cracking.

The second picture shows the location of cold joint which is horizontal but the crack is almost vertical . My opinion is ,the crack is at the cover and seems to be the fresh concrete was not placed and vibrated properly .
I will suggest you to break the cover along the crack and see the depth and ask a few core test .If you are convinced for the strength then ask to repair the cover with mortar ( similar to SIKA monotop repair mortar etc).

 

[Enhineyero]

I have actually have seen worst, this isnt that bad.

You can try and fix using grout (or other retrofit solution) then finish the column with plaster or something similar (to provide secondary protection). Obviously, you still have to assess the design stress where the crack is located. Its likely that that bending and shear due to lateral loads is small at mid height of a column, so there is that.

 

[gte447f]

The crack doesn't look vertical to me. It looks more diagonal, so I don't think it is necessarily just cracked at the cover beyond bars. Also, if the crack, being so steeply diagonal is really aligned with the cold joint, then that is problem to me. The cold joist should have never been "finished" or left in that condition between pours. The cold joint should be near horizontal. I do not know if there are ACI guidelines for tolerances for such things, but I would think that there might be. For just one column, in residential construction where labor tends to be less experienced and more unskilled, I would consider recommending demolishing the column and rebuilding.

 

[NFExp]

Thanks for all your reply's. I received some additional photos today and it looks like the 2nd pour was not consolidated. The voids in the photo are significant. These photos were sent from the contractor and I have not done my inspection yet. From what I am told, this is the only column that is having issues and this is the only column that was poured in 2 pours.

Due to the amount of voids, I don't see how its possible to chip out the concrete and patch.

 

[TRAK.Structural]

Before telling them to tear it down and rebuild, you could require them to chip it back to sound material to see how much of the section is actually affected. Then you can make a determination on what to do.