Shear Testing

As part of the engineering plan for seismic retrofits, a shear test is required to determine the strength of the original mortar in the hotel walls. In preparation for this test, one brick is removed from the wall and one vertical mortar joint is removed from the far side of an adjacent brick.

Shear 01

Into the hole left by the missing brick, a hydraulic ram is inserted.

Shear 02

Shear 03

A hand activated pump will cause the ram to exert force against the adjacent brick with the goal of sliding the adjacent brick into the space left by the missing mortar joint. Once that happens, a gauge on the pump will report how much pressure was exerted before the mortar failed allowing the brick to slide.

Shear 04

Something to note on this particular test is that the wall is painted with latex paint which, in this case, served to protect the brick making it one of the strongest walls of the building. This runs counter to what I’ve been reading about old brick walls and their need to breath. Moisture being trapped inside bricks by paint is supposed to hasten brick deterioration but apparently, Nevada is so dry that moisture doesn’t get trapped in the first place. This makes the project a lot easier since I don’t have to worry about removing all that latex paint from the masonry.

Now, everyone please send your good thoughts. Once the test results are in, the structural engineer will create his plans and we’ll know if this project is financially feasible.

Author: Glenn

I'm a 5' 8" tall ape descendant with an interior design degree and a love for antiques and vintage architecture. I recently escaped from the IT world to follow my dreams and a beautiful damsel who shares my love of old buildings no matter how much dust is involved.

4 thoughts on “Shear Testing”

  1. May your mortar be strong, and the bricks as well, may you all avoid, a brickyard hell!

  2. I always get scared with tests like this, hope it doesn’t bring the bricks tumbling down!

    1. Well, the common thought is that the structure has been there for over 150 years and there are worse breaches in the masonry from remodels so it’s not likely to collapse now. Also, I’ve learned to trust my intuitive senses over many DC projects and I’m not getting any alarms over this. I think we’re still good.

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