Does Flexural Reinforcement Count for Shear Friction
Does Flexural Reinforcement Count for Shear Friction
(OP)
Can you count the flexural reinforcement across a wall construction joint in calculating the shear friction reinforcement needed to transfer the shear into the footing..? ACI 318 is not clear on that..!






RE: Does Flexural Reinforcement Count for Shear Friction
RE: Does Flexural Reinforcement Count for Shear Friction
I have never done anything more than calling for "intentionally roughened surface" when designing retaining walls. The question is do you count both tension steel and compression steel or only the tension steel for shear friction.
RE: Does Flexural Reinforcement Count for Shear Friction
DaveAtkins
RE: Does Flexural Reinforcement Count for Shear Friction
RE: Does Flexural Reinforcement Count for Shear Friction
thread507-226141: Can I count on shear-friction capacity of the reinforcement?
RE: Does Flexural Reinforcement Count for Shear Friction
RE: Does Flexural Reinforcement Count for Shear Friction
Quoting ACI R11.6.7, "When moment acts on a shear plane, the flexural tension stresses and flexural compression stresses are in equilibrium. There is no change in the resultant compression Avf*fy acting across the shear plane and the shear-transfer strength is not changed. It is therefore not necessary to provide additional reinforcement to resist the flexural tension stresses..."
I don't know how it can be more clear.
DaveAtkins
RE: Does Flexural Reinforcement Count for Shear Friction
This assumes that the designer first provides the shear friction reinforcement and distributes it according to 11.7.8, and then check to see if additional reinforcement is needed for moment.
You'r doing it the other way around, by first providing the flexural reinforcement and then checking shear friction. It's not the same. The difference is that the shear friction reinforcement must be distribututed along the shear plane according to 11.7.8 (see PCA notes, chapter 14), not concentrated at the tension face.
The classic application for shear friction is a corbel. The Ah shown in Fig. R11.9.2 and required by 11.9.4 shows the required shear friction distribution.
RE: Does Flexural Reinforcement Count for Shear Friction
DaveAtkins
RE: Does Flexural Reinforcement Count for Shear Friction
Thank you all for the valuable comments.