Precast Wall Panel - Keyway Footing

[dcl54]

One of the precast wall suppliers I work with has indicated that the typical grouted keyway footing detail is no longer considered acceptable. I have searched for documentation to confirm this with no luck.

Has anyone else encountered this situation?

Thanks!

 

[civilperson]

The keyway design which has a 2"x4" pultrusion into the other shape is worthless. Imagine a crack which can go anywhere. The two re-entrant corners will define a stress concentration from which a crack can traverse, negating any shear contribution from the pultruding concrete. Steel crossing the plane of the construction joint and a slightly roughened surface with the concrete laitence removed is the gold standard for transfering stresses across the joint. If water stop is added then the joint is the best for water containment.

 

[hokie66]

I don't think that is the type keyway the OP was talking about. He didn't get any response until now, so I guess no one had any advice. I would read his question as applying to the type footing which is cast with a big slot for precast panels, then grouted after erection. But perhaps the OP can clarify and try again.

 

[dcl54]

hokie66 is correct. The detail I am referring to utilizes a 3" deep keyway cast into the top of the continuous wall footing. The width of the keyway is typically the thickness of the precast wall panel plus 3". The panel is set on a ship pack in the keyway and grouted into place.

Hopefully, this clarifies the situation I tried to explain in my first post.

Thanks!