Page 505 - Forensic Structural Engineering Handbook

13.50 MATERIAL-SPECIFIC FORENSIC ANALYSES

should have been had an expansion joint under the shelf angle been provided in accordance
with the building code. Flexural tensile stress in the masonry at design wind load was esti-
2
2
mated at 147 lb/in . Mean flexural strength of the masonry was estimated at 140 lb/in for
the type of mortar and workmanship specified. It is probable that more than one-half the
masonry would have cracked had the specified mortar been used.
The contractor left holes in mortar joints, did not fill all mortar joints, used insufficient
cement in the mortar, used about one-half as many wall ties as required, and did not prop-
erly install shelf angles. In addition, the contractor did not provide an adequate expansion
joint under all shelf angles, and may have used a mortar admixture in violation of the law.
The contractor did not keep the wall cavity clean, frequently bridged expansion joints, and
did not properly install some masonry connectors. These violations of the law and breaches
of contract caused the walls to crack and to leak.
Sealant joints at windows, expansion joints, and shelf angles were not well maintained,
which permitted wind-driven rain to enter the wall.
Extensive repairs were recommended, including immediate repair in some areas to pro-
tect public safety.

REFERENCES

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Conditioning Engineers, Inc., Atlanta, GA, 2005.
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Testing and Materials, West Conshohocken, PA, 2008.
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Climates, The Hospitality Lodging & Travel Research Foundation, Washington, D.C., 1991.
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of Building Sciences, Washington D.C., Summer/Fall 2008.
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Contractor, Wiley, New York, NY, 1986, p. 383.
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The Masonry Society, Boulder, CO, 2008.
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Society for Testing and Materials, West Conshohocken, PA, 1975, pp. 133–139.
13. C. T. Grimm, “The Color of Structure,” Journal of the Structural Division, Proceedings of the
American Society of Civil Engineers, Reston, VA, September 1975, p. 1871.
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West Conshohocken, PA, 1982, pp. 178–199.