Installation of Horizontal Temperture/Shrinkage Reinforcement in CMU

There is no advantage in tying horizontal reinforcement to vertical reinforcement other than perhaps to hold the bars in position.

ba/ael is probably right except that if you are intending the structure to be earthquake resistant there is probably a need to address the shear connection between the two elements - but I'm not a civil engineer so I can't add any more than that.

You must tie the reinforcement = Anchoring the cantelever to the reinforced wall by bending appropriately the cantelever reinforcement into the supporting structure.

Warning: If you are not qualified to design such a structure, you are taking unnecessary risks. Can't advise you without a drawing to show what you are exactly doing. You message/question is very badly worded and lacks clarity...

LAA Luke,

Thanks for the information. Yes, I am a Civil Engineer and qualified to design these structures, but new to the design of CMU.

I could not attached a pdf document to the message for your review and information.

John

There is no reason to tie the horizontal bars to the vertical bars in masonry construction and is not common paractice. I am assuming that you are talking about hollow block walls.

Reinforcing bars are tied together in reinforced concrete construction to hold them in the correct position until the concrete has set. The wire ties are not capable of transferring any significant forces between the bars. Any load transfer is done by the concrete.

Short of having a clear picure of how the cantilever is anchored on the wall:

- If the cantilever is extending a decking, then the reinforcement should be either extended from the decking or, if added, the addition should extend into the decking for at least 30 - 40 cm. Horizontal bars are as you mentioned correctly...

- If this is a brick wall, the cantilever reinforcements cannot rely on being anchored by simply adding some horizontal bars on top of the brick wall (making a kind of beam): This is why you need to work out the size of the cantilever (protrusion ... ) with the wall width, and maybe you need to produce a hefty lintal/beam to balance your cantelever... Civil engineer who did not forget how to work it out OR with experience in the field of such design is required at hand: He should consult nearby!

LAA Lucke,

You have misunderstood the terminology here.

A cantilever retaining wall refers to a wall anchored to its foundation with no support at the top. I has nothing to do with a deck cantilevered from the top of the wall.

KDELTA

Thanks for the clarification. You are correct.

There is lots of information on the internet about this which can be found with the aid of Google. Here are a few links you might want to try.

Horizontal reinforcement should not rest on top of the blocks, but it does not need to be tied to the vertical bars except as may be required to hold bars in position while pouring concrete. These details used by Fairfax County show one method of placing reinforcement. See pages 4, 5 and 6.