Unreinforced concrete walls

[MIStructE_IRE]

Hi,

I have unreinforced plain concrete walls which provide vertical support to a flat slab roof. These walls are internal walls with slab both sides and no wall above.

Essentially the rebar simply runs over the wall and the plain wall is therefore not tied to the slab with L-bars - ie its detailed as if it were a masonry wall.

Since its providing vertical support only, I dont see any other reason that it should be tied. Am i missing something? Non seismic zone by the way!

Thanks

 

[Tommy385]

Cracks are posible. If you can live with them I don't see any problems.(if the wall can take the load without rebar)

 

[BAretired]

Whether it is a concrete wall or a masonry wall, it is simply good practice to provide ties, reasonably spaced between wall and slab. Otherwise friction is the only force that holds wall and slab together.

Ties would certainly be required if it was in a seismic zone, but even in a non seismic zone, there can be pressure differences across internal walls.

I suppose it could be considered a case of using engineering judgment. In my view, to omit ties is to exercise poor engineering judgment. The omission of ties has negligible effect on project cost.

BA

 

[MIStructE_IRE]

Thanks guys,

I should have mentioned, I would still be providing vertical ties at max 5m crs as per the code. This question relates to standard L-bars at say 200mm centres. Even if they were provided they would not be ‘tied’ to anything in the plain concrete wall.

 

[BAretired]

5m centers seems a bit sparse, but better than nothing I suppose. 1200mm o/c seems to me a better choice.

BA