Development length provided by U bars
Development length provided by U bars
(OP)
If you have an RC slab rigidly connected to an edge column, and there is little depth in the column to cater for the required development length, is it possible to use a U bar at the edge of the slab to give you sufficient development? For example, say you have a 150x150 sq column, and the tensile reinforcement coming from the your slab needs at least 500mm of development.






RE: Development length provided by U bars
RE: Development length provided by U bars
BA
RE: Development length provided by U bars
RE: Development length provided by U bars
You say.... “Just a hypothetical, albeit unrealistic.” It is almost as easy to think just a little bit and be semi-realistic with your hypotheticals. That way, we don’t start from the very beginning thinking that this guy has no idea what he’s talking about or doing, why should we help him? On the one hand we do understand that many times the general concept of the problem is not really a direct function of some dimensions. But, you would be surprised at how proper and realistic proportions, dimensions, loads, bar sizes, etc., influence an experienced engineer’s view of a problem and his first impression of it feasibility or stupidity; and then how he answers the question.
RE: Development length provided by U bars
RE: Development length provided by U bars
The Indian codes let you make up for the development length by extending the tail of the hook.
RE: Development length provided by U bars
At corbels I have always understood that the bars had to be developed. Surely, for instance, you couldn't effectively use a #8 U bar in a 10" column and have it developed. Just my 2 cents.
RE: Development length provided by U bars
By ACI 318-11 11.6.8, bars intended to engage shear friction (as in corbels) are required to be fully developed on each side of the shear plane.
In the case of tension, you are required to develop the bar(s) in proportion to the demand, where there is more reinforcement than the minimum required. [ACI 318-11 12.2.5, 12.5.3(d)] This partial development (i.e., shorter development length) might be applicable in the example you suggest.
RE: Development length provided by U bars
I think the confusion is due to the question. The U-bar will develop the slab reinforcement. But the connection to a column is a separate issue. There was not enough information in the OP's question to know what he is trying to achieve in that regard.