Precast Panel Repair

[jerseyshore]

Went to a building today with some classic late 60s/early 70s architecture, the highlight being these precast panels. They are not only the exterior facade, but also in half of the interior side of the building too. Man the 60s must've been weird.

Anyway, on two corners the panels have started to pull away from the backup. The building appears to be mainly block walls, but Photos 2 & 3 are at a double cantilever overhang, so there might not be block there.

Any thoughts on a simple repair here? I was thinking some masonry anchors, Helifix or Simpson or similar anchors (assuming there is block behind). I don't do a ton of precast panel work, so not overly familiar with the repairs. Appreciate any thoughts.

 

[GeorgeTheCivilEngineer]

Yikes - it looks like there are a few other cracks appearing. If the fixings/panels have failed at the corner then I would think the rest might not be far behind.

You will need more information so removal of a few and close inspection is required. Reinforcement may be possible, but I would not rule out replacement. In the mean time, an exclusion zone should be established to keep people away from that area.

 

[JohnRwals]

This repair may not be simple.
Immediate action should be done; be prepared for the potential failure!

 

[phamENG]

I'd start by removing the offending panels. What failed? Was it the ties? Was it a wood framed backup over the cantilever that's rotting due to a roof leak? (Wood is unlikely, but you never know - the 60's were weird...I think)

Until you can be confident in what it is your trying to repair, you need to keep digging.

 

[XR250]

Yea, might be a mess behind 'em. I wonder if water got in there and froze?
Def. above my pay grade to address something like this.

 

[JStructsteel]

Those need to be removed and the back up support checked, along with other connections. Last thing you want to be involved with is one of those falling and hitting someone.

 

[jerseyshore]

My first guess was water getting back there and freezing, but everyone here is right, we need to have them take off these panels and reveal what's going on behind. It was very sunny yesterday and it looks worse after looking through my photos, especially the second and third pictures. Looks like a weird stepped crack type fracture, not just splitting at the panel joints.

 

[Prestressed Guy]

You say precast panels but that looks like it might be some type of concrete veneer that is attached to the underlying structure. If that is the case, it is likely that the veneer can be removed and replace after fixing the underlying structural problem which caused the cracking. Given the diagonal inclination of the crack pattern it would appear that the cantilever is seeing significant deflection.
I would think first step is to barricade the space below and that done today.

 

[jerseyshore]

Yeah it's definitely veneer. Probably a hung panel off of whatever the backup is. I should've said veneer instead of panel in my title, good catch.

 

[bridgebuster]

See attached details. They're repairs for brick veneer on bridge abutments and retaining walls but they might give you some ideas for a temporary fix. I agree with Pham, if you're looking for a permanent repair you'll need to remove panels.

About 20 years ago I did a temporary repair project at a mall in Nanuet NY. The stone block veneer was separating from the plywood backing, there was also sheet asbestos insulation. In some locations all the block was removed because the bulging was too much. In most spots I used a variation of the repair on Page 2 of the attachment. I couldn't use coil rod because of the plywood. Instead I used butterfly bolts; it worked. The crew used a HEPA drill to deal with the asbestos.

Pham - the 60's were weird. I don't know about the engineering part - maybe Dik can weigh in - but they were weird.