Masonry Magazine October 2003 Page. 15
Top anchor-
Bottom anchor
Concrete
masonry wall
THE "POST"
SPEED LEAD
Tendon
Courtesy of Ledy Design Group
Figure 1
Simply stated, prestressing adds compression to masonry. For example, Figure 1 shows a single-wythe wall with a tendon. The tendon has anchors and bearing plates at the top and bottom. Once the masonry is constructed, the tendon is stressed which compresses the wall. Depending upon the actual design, there may be little or no grout used in the cores, which reduces time and money.
Why would we want to do this? Masonry is very strong in compression. Prestressed masonry compensates for any external forces (wind, earthquakes, earth pressure, etc.) that would normally cause the wall to bow and crack from tension by using masonry's strength under compression.
Is prestressing really new? Not really! Figure 2 is copied from the design drawings of a 1960s building with brick parapets. In the figure, the parapet is "clamped" down to the edge of the roof with an anchor rod and steel plate. The bottom of the rod is anchored into the roof slab. Masons know that tightening the rod effectively compresses the parapet wall and makes it more stable.
Steel plate with
nut and washer
Anchor rod with
hook in roof slab
Quick set up.
Quick take down.
Fewer parts.
One bracket assembly.
• Ideal for all applications of
brick veneering.
• Inside, outside, quion, and
angled corners.
• Invented and patented by a
bricklayer.
For information write or just call
(800) 525-8287
Marv Post Enterprises Inc.
2858 Sibley Hills Drive
Eagan, MN 55121
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STERLING
The "TOUGH GUY"
Brick BarrowWS
First choice of
masonry contractors,
STERLING brick barrows
are made in the U.S.A.
and built to last.
Courtesy of Ledy Design Group
The Voice of the Mason Contractor
Roof slab
Figure 2
Phone or fax for
complete information.
STERLING
HANDLING EQUIPMENT INC.
PO. BOX 090438, MILWAUKEE, WI 53209
Phone 414-228-7728 FAX 414-228-9032
www.sterlingtoughguy.com
vip@sterlingtoughguy.com
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October 2003
Masonry
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