Concrete Expansion

Cracks in Brick Veneer
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Cracks in Brick Veneer

Q: I have noticed many vertical cracks in the brick veneer on a recently completed... More

Expansion Joints for Windows
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Expansion Joints for Windows

In many buildings that have rows of closely spaced windows, it is almost... More

Installing Expansion Joints
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Installing Expansion Joints

I have a wall system with multiple windows spaced closely together with arches. As... More

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Mason's Toolbag

A number of companies introduced new products during the World of Masonry. Here are a few of those that hit the market during the Las Vegas show. More

Replacing Flashing
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Replacing Flashing

My company is currently replacing the flashing on a building because of leakage... More

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Foam or solid joint fillers?

On a recent project, I specified the use of Neoprene foam fillers for expansion joints in the clay masonry walls. The contractor, however, installed solid Neoprene control joint fillers like those typically used in concrete masonry walls. Is this substitution acceptable? More

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Is more joint reinforcement needed?

An adjustable hook & eye horizontal joint wire reinforcement will be used in an exterior cavity wall system consisting of a 12-inch concrete unit masonry backup, 2-inch rigid insulation, 1-inch air space, and 4-inch concrete unit masonry veneer. This reinforcing will be installed at 16 inches on center. Since the veneer is 4-inch ground face concrete unit masonry and not face brick, is it necessary to install an additional 4-inch joint reinforcement within this wythe as well? More

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Adding expansion joints

I have an interesting dilemma at a building that my firm has been hired to repair. Shrinkage of the concrete frame over the last 30 years, along with expansion of the brick masonry, have caused the masonry to move upward relative to the concrete frame. Angles attached to the concrete spandrel beam use wedge inserts cast into the beams. I am afraid that some of the anchors in these wedge inserts may have become loose as the angles shift upward. How can expansion joints be added beneath the shelf angles to accommodate any future movement without the angle just shifting down because the anchors are loose? More

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Using Steel Relief Angles in Masonry

I recently read a technical paper that provides exhaustive data for engineered design and detailing of "relief" angles. However, the article does not discuss when – if ever – it is a good idea to incorporate relief angles into a structure, except to acknowledge in the conclusion that states: "Severe damage can result from the improper design, construction, and maintenance of shelf angle details."Since maintenance, and to a large extent construction, are beyond the control of even the most conscientious engineer, I was wondering if you or any of your peers have written a paper with rational criteria for the incorporation of steel relief angles into masonry structures with, hopefully, some considerations for designing the veneer to resist wind loading at interruptions and discontinuities.I have BIA technical note 28B (1980) which recommends: "In order to alleviate the many problems associated with the use of shelf or relief angles at each floor, it is suggested that the brick veneer may be designed to support its own dead weight on the foundation, unless heights (in excess of 100 feet) or number and location of openings in the veneer make it mandatory that walls be vertically supported by the structural frame."We have been happily following this rule of thumb for many years by reinforcing the perimeter of veneer openings and providing lateral anchorage consistent with the UBC wind load requirements. Recently we discovered that our approach was considered "unorthodox" and "unconventional" in some engineering circles. We were shocked to discover the aesthetic, cost, and detailing implications of trying to inject relief angles at every floor of a four-story institutional buildings which we had previously been designing successfully without a single relief angle. I reviewed more recent BIA documents and found that the language I quoted had been deleted. Is something going on in academic and/or professional circles to squelch relief angle free veneers? More

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Cracks at Corners

IÆm involved in a repair project on a building where there are vertical cracks near the corners. However, the crack patterns on this project arenÆt like those I have seen before.First, the building has vertical strip windows that alternate with 10-foot-wide masonry piers between the windows. With these piers being only 10 feet wide I think there would not be very much horizontal expansion.Next, these cracks donÆt extend to the full height of the corner but run only at the level of the shelf angles.Finally, this building was built during the 1960s, and the shelf angles were installed without any expansion joints beneath them. The top of the wall is restrained on the underside of the concrete roof system, which projects from the building as an architectural statement. It seems like unrelieved vertical expansion may be part of the problem. I am not sure what is causing these cracks. Any ideas? More

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