Concrete Wicking?

[PCHanson]

I have observed a 10' high walk-out basement foundation wall/dividing wall between two condo units. The concrete was poured around 10/06. The wall terminates at the rear exterior (walk-out side) which is stud framed on frost wall. The lower 2' of the separation wall has a 2'x2' diagonal through crack running from top (ext.) to bottom (interior) with 3/16" max. width at the base. There is possible issues of subsurface water drainage on the outside leading to the foundation. Obviously this crack could be from shrinkage or even if the wall was bumped, but I do suspect erosion under this "pier", that it heaved, or that the pier is "hung" off the tall interior wall and that this is a shear crack. I point out the condtion to pose the question: the last 3' to 4' of this separation has significant dirt/dust on the entire height of it...on both sides of the wall. Both owners are adamant that it did not exist (not visible) intitially. It is possible that the nearby walkout patio door and windows were left open, but the line of "dusting" appears too extreme and seems unlikely this event happened at the same time. Is it possible that water is wicking up the concrete and allowing even coarser grained soil to come to the surface? Or is it more probably that the last form panels had some sort of coating that has caused this last width of concrete to "collect" air-borne dust?
Thanks in advance for any insight.

 

[youngstructural]

Sorry but I really can't follow this...

I think you need to upload a new photos and at least one sketch of what you see. There are lots of great members waiting to help you, but the question needs to be clear.

Cheers,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...

 

[concretemasonry]

Diagonal cracks are tip to look at possible footing problems.

The other items point towards possible wet concrete and poor placement. Both of these can be common on some condo problems.

Just 2 guesses with based on a quick reading. Photos would be a great help to fully describe the situation.

Dick

 

[cvg]

you will probably not get sufficient flow (volume or velocity) through a 3/16" crack in a concrete wall to carry coarse grained soil without also observing the corresponding water spout and flooding mess on the floor. However, you might get enough to carry some very fine grained (clay or silt) particles through. You could also be observing a mineral deposit or even efflorescence.

 

[hokie66]

I can't help with the dirt on the wall, other than to say I suspect it is unrelated to the crack.

The crack sounds like a typical restraint shrinkage crack. The top of the wall was free to shrink, while the bottom of the wall was restrained by the footing and pier. It takes a lot of well developed reinforcing in the bottom of the wall to control that type crack. If the pier was capable of resisting a substantial uplift force, you would have had both the vertical pier force and the horizontal footing force restraining the wall shrinkage.