Water Reservoir Wall Cold Joint

[BouncedPod]

We are currently in the process of constructing a water storage reservoir with 16' high 12" thick concrete walls. When I was on site, I noticed a cold joint approximately mid height and the full length of one of the walls (see the attached photos).

The contractor said that they got a batch of dryer concrete that led to the cold joint (even though plasticizer was added to the mix). What does everyone think would be the best fix for the problem? I have been tossing around the idea of epoxy injection or using a non-shrink grout with an epoxy paint finish. As far as the strength of the wall is concerned, the vertical wall bars are continuous from top of footing to top of wall, and there is plenty of reinforcement when considering shear friction. I am more concerned with the water penetration into the wall than I am with the strength of the wall.

 

[TehMightyEngineer]

I agree, I'd fix this to limit water penetration. How deep is the cold joint? I'd not plan this fix until this is known.

Ian Riley, PE, SE
Professional Engineer (ME, NH, VT, CT, MA, FL) Structural Engineer (IL, HI)

 

[hokie66]

It's not just the cold joint which would bother me. Your pictures indicate a lack of compaction throughout. Not acceptable, particularly for a water retaining structure. I'd be looking at a membrane.

What's the deal at the left end of the wall? How is that to retain water?

 

[MIStructE_IRE]

What pour rate (height per hour) is he using? I don’t believe that’s a dryer batch on top.. I think that he poured too fast, didn’t compact/vibrate correctly and dumped a fresh batch in on top following some unforeseen delay - and again, did not vibrate/compact.

As above, whats happening at the left hand side? Are you using cast-in waterbars? Is there a watertight concrete admixture?

 

[BouncedPod]

hokie: The reservoir is to be poured in multiple sections with water stopped and sealed control joints in between pours. The left end of the wall is a control joint.

MIStructE: I was on site to watch them pour the same amount of concrete on the opposite side of the reservoir, and they poured 62' of wall, 1' thick, and 16' tall (less than 40 yards). They did this in about 1.5 hours and had no delays. I agree, I don't think they had a dryer batch on top. I believe they started pouring on the cold joint side, filled the wall half way and continued around to the other side. I believe they filled the opposite side full and then worked their way back around to the cold joint side. The time in between lifts combined with insufficient vibration is what led to the cold joint.

 

[GC_Hopi]

An injection would be a solution, Link and hopefully its painful for the contractor so that will reinforce the idea of proper consolidation to the contractor. But not painful enough where they do a bad job.

 

[hokie66]

BouncedPod,

Control joint. Do you have a plan to prevent the two sides of the control joint from moving individually? Dowels?

 

[bones206]

I think an injection fix is feasible if it is truly just one cold joint that can be visually traced from start to finish. You just need to determine the right product (get a Sika rep out there) and find a good experienced specialty contractor to do the injection work (ask the Sika rep for recommendations). The right product will have low viscosity to find all the nooks and crannies and is designed for service under constant water pressure. A hydrophobic urethane grout that expands after contact with water may be a good option.

 

[BouncedPod]

hokie: Yes, dowels will be installed at the control joints to prevent the wall sections from moving independently.

I am leaning towards specifying either SikaFix HH Accelerator or Simpson Strong-Tie ETI-SLV injection epoxy.

 

[bones206]

SikaFix sounds promising but the Simpson epoxy doesn't seem as suitable. I always seek the opinions of a Sika rep and a repair specialty contractor, since they generally have the experience to know which products work best for a given application. If the contractor offers a warranty on the repair, they have even more incentive to give a good recommendation.

 

[nackra]

Early in my career I had a wastewater treatment plant project that had significant issues with concrete placement and consolidation (some voids were through the entire wall). After arbitration, leaks were repaired with SIka products and an AWWA leakage test was performed:

https://www.concrete.org/publications/internationalconcreteabstractsportal?m=details&i=4193