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Distressed CMU exterior wall

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smb4050

Structural
Jul 19, 2006
89
The situation is another expert witness, an architect, is claiming the webs of 12" fluted/corduroy CMU’s have cracked or disintegrated allowing the exterior face of the units to bow out from vertical, and he stated the reason the web(s) cracked was due to freeze thaw due to moisture infiltration into the wall. Using a fiber optic scope he looked inside the CMU cavities and saw the webs were broken, and I take him at his word. The wall definitely has moisture infiltration problems as evidenced in the attached photo. The building was built in 1972 and is located in a northern climate with the average January temperature being around 20F. The exterior faces west and the interior space is storage and loading dock area, but is connected to a heated space (discount department store). The interior face is unfinished and the wall is not insulated. Over the years the building has had little or no maintenance. The building’s structure is steel post and beam with steel joist and deck, and the CMU walls being an infill between columns and to the bottom of the perimeter steel beams. I did not see lateral bracing in the construction documents or in the building. The 12” CMU has horizontal joint reinforcement @ 16” centers. In the attached photo vertical course is a 2” sailor with 2 courses of 8” CMU’s below, covering the perimeter beam. The steel beam has 1/8” x 8” strap masonry clips @ 32” centers at their bottom and web to anchor the masonry to the beam.
I have never seen the web of CMU crack due to freeze thaw cycle, and my concern is the problem is more complex and due in part or solely to stresses from lateral and vertical loads being transmitted into the block. My questions are has anyone seen a similar problem with the exterior face of a CMU separating and if so what was the cause of the separation, and has anyone see the web crack due to moisture freezing?
Hopefully I’ve included enough information for anyone interested in providing any comments.
Thanks
 
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The attached drawing shows the dimensions. A point of reference, both previous photos are looking north.
At some time this past summer the owner had the wall covered with metal siding, so I can no longer easily get measurements, but from old photos I've counted flutes and came up with the dimension shown. There is a roof expansion joint shown at grid 5 with a note on the structural stating all beams and joist to have slotted connections on one side of the grid line/beam, and on the architectural there is a note calling for control joints in the masonry at each column. According to the roof details the roof expansion joint shows the metal deck also being seperated.
This is about all the information I can provide outside of a few more photos.
Thanks again for the comments.
 
 http://files.engineering.com/getfile.aspx?folder=e6418ff1-d5f6-4227-859a-f1fc764ae32a&file=Layout_PDF.pdf
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