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Precast Panel Cracking

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Fellow Engineers;

 

I received a call from a friend of mine at a precast plant that has a fairly big problem with a particular job.

The owner is complaining about water leaking through the face of the panels and streaking into the building. This leaking is leaving deposits on both the outside and inside of the building

 

The building layout:

 

The building is a precast stage tower about 100 feet tall.  The panels are a non-composite panel consisting of an 8” solid structural Wythe with two layers of prestressing both 1.5in from either face, a two inch layer of insulation, and a 2.5” face with 4 ¼” prestressing strands pulled to about 2500lbs.  (This is a Spancrete panel with the cores pulled out.)  The building has four columns, two on wither side of the plenum opening, and two on the opposite wall however they are not directly across from each other, they are offset about three feet of so.  The building is about 102feet x 47feet with the columns on the long wall.  The panels are horizontal, not vertical, and are supported by the panel below them for gravity loads.  The panels on the long wall are in three pieces, (welded connections to the columns) and have welded connections to the short wall panels, which are one piece.  The short wall panels are supported by the long wall panels.  These panels are load bearing and support all the stage rigging, roof, platforms, and all the other items required in a theater production.

 

The problem is this:

 

The panels have all cracked about 2’-0” in from each end in the face only, not just a few but all!

ALL welded connections have cracked.

The panels have also cracked horizontally along the center of a panel; this is the same location as a reveal.

 

Besides deflection, and creep what would cause this to happen? 

Have any precasters or Engineers designed the face of panels to try and predict the cracking?

 

If any of you can shed some light on this it would be extremely helpful.

 

 

Thanks in advance,

 

 

Chad Van Kampen

Gerace Construction