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Unreinforced Masonry Building

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A few weeks back I sent out a request asking if anyone knew how to conduct non-destructive testing to determine if reinforcing and grout was placed in the voids of an existing masonry building.  I appreciate the responses that I received from many of you.

Well guess what.  There was only grout and reinforcing in the horizontal bond beams which were placed at 4 foot centers horizontal, in the lintels, and vertically at each side of the expansion joints and openings.

Now heres another one for you, there are 15 of these building designed by our office and from what I recently heard 12 more that were designed by another.  

These buildings are telecommunication building in Texas which is in seismic zone 0 with a 80 mph wind speed.  I haven't checked yet but I believe that #4's at 4 feet on center will work vertically.  

Now to retrofit this building I am considering having them saw cut and remove the inner shell of the block from the inside, embed #4 bars into the upper and lower bond beams with epoxy grout ,lapping the bars 30 inches, then gluing the shell back up to the course just below upper bond beam, then filling the void with grout continuing up carefully and adding the last shell and pointing the remainder.

What a mess, If anyone has a better idea I would sure like to hear it.  Adding shotcrete with a grid of steel to the interior is not an alternative.

I would appreciate your suggestions.

David A. Hall, S.E., P.E.
Senior Structural Engineer
David Evans and Associates, Inc.
2828 SW Corbett Ave
Portland, OR 97201
Fax 503-223-2701
E-Mail dahl(--nospam--at)