Shear Strengthening - Concrete Joist
Shear Strengthening - Concrete Joist
(OP)
thread507-221830: Existing Beam - Added Shear Capacity
There is an existing concrete floor system that is comprised of 12" deep precast joists with a 3" composite concrete topping. There is a change is usage of the floor and subsequent increase in loading.
What are the options for strengthening the beam without doing fiber reinforcing, adding channels etc.?
See attached sketch. The rib above the joist has ties and flexural reinforcing. The rib is in turn connected to the joist using single doweled bars.
My question is:
1. How far should the dowel bar be embedded such that both the sections can act composite for shear.
Does the detail even work?
The bar will be checked for horizontal shear transfer. The surface will be roughened to 1/4" amplitude.
There is an existing concrete floor system that is comprised of 12" deep precast joists with a 3" composite concrete topping. There is a change is usage of the floor and subsequent increase in loading.
What are the options for strengthening the beam without doing fiber reinforcing, adding channels etc.?
See attached sketch. The rib above the joist has ties and flexural reinforcing. The rib is in turn connected to the joist using single doweled bars.
My question is:
1. How far should the dowel bar be embedded such that both the sections can act composite for shear.
Does the detail even work?
The bar will be checked for horizontal shear transfer. The surface will be roughened to 1/4" amplitude.






RE: Shear Strengthening - Concrete Joist
RE: Shear Strengthening - Concrete Joist
BA
RE: Shear Strengthening - Concrete Joist
RE: Shear Strengthening - Concrete Joist
RE: Shear Strengthening - Concrete Joist
Indeed we are talking at cross purposes. The dowels have no value as stirrups, but they do have value in transmitting horizontal shear betweeen the two joists.
BA