Control Joints In CMU Shear Walls
Control Joints In CMU Shear Walls
(OP)
Help!!!
I have a 48'x72', three story masonry structure that needs control joints. The wall openings set by the architect determined my shear walls locations. Can you place a control joint in a shear wall, say at the neutral axis or to heck with it and not place any joints letting the building crack?
TIA
I have a 48'x72', three story masonry structure that needs control joints. The wall openings set by the architect determined my shear walls locations. Can you place a control joint in a shear wall, say at the neutral axis or to heck with it and not place any joints letting the building crack?
TIA






RE: Control Joints In CMU Shear Walls
RE: Control Joints In CMU Shear Walls
The way I've always approached it is if the horizontal reinforcing is running continuously through the joint, then I treat it as a continuation of the adjacent wall. However, if the reinforcing is stopped, then I treat it as you have stated.
RE: Control Joints In CMU Shear Walls
If the reinforcement runs continuously through the joint, then how do you have a joint?
I think that UcfSE is right and you have two walls beside each other. It takes a very strong vertical shear connection to force the two walls to act compositely. By the way, the neutral axis is the location with the most shear -- think VQ/I...
Good luck.
DBD
RE: Control Joints In CMU Shear Walls
RE: Control Joints In CMU Shear Walls
Bond beams for crack control should not be continuous across the CJ. CJ's are recommended to encourage cracking in contoleed locations when CMU shrinks, so you can prevent water from penetrating the wall. With brick, the you need joints to allow for expansion of the brick due to moisture absorbtion by the brick. If you don't have them in brick, you will probably see distress, especially at corners and any offsets as the brick grows. A brick parapet without joints can suffer a lot of distress. Joints in a brick veneer and a CMU backup should line up.
RE: Control Joints In CMU Shear Walls
RE: Control Joints In CMU Shear Walls
Please explain "most likely"?
STR04
RE: Control Joints In CMU Shear Walls
First, if the load is large enough, it could cause the two walls to act like a hinge and fold at the construction joint (or fail from the flexure whichever comes first).
Also, if there is a significant seismic load, it could cause the walls to heave out of plane.
Not being familiar with the design parameters, I made an educated guess that neither of those events is likely to occur. But of course it depends on your seismic and wind loads. Hope that clarified my previous response.