28. Worked example #10: Bending and shear design

Reinforced Concrete Design to EC2
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Questions and discussion for this lecture live here. Fire away by hitting Reply below :fire:

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Hi Sean

I’m having trouble understanding what you mean by ‘4H10 links per plane.’ Could you please provide me with a visual example or a real-life illustration to help me better comprehend this concept? I would greatly appreciate it.

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This just means that if we were to take a cross-section through the beam at a plane where we have provided shear links, there would be 4 vertical shear link bars. So, in lesson 28 at about 28:04, when I show the image of the cross-section, you can see the 4 vertical bars (these are the shear links) in that section or plane.

So, if we increased the spacing between planes, we would need to provide more vertical bars per plane. Conversely, if we reduced the spacing between planes we could provide less vertical shear reinforcement per plane.

S

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in 10:30 isnt the Maximum zbal = 0,82d ?

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Hi @Kalem_AbdelDjalil,

0.82d would be the minimum value of z - i.e. the the value of Z for a balanced section design. In this scenario, the concrete compression block would be at it’s max capacity.

So, values of z larger than 0.82d (up to 0.95d actually) are OK, since these would correspond with the concrete compression block being smaller.

Let me know if that’s not clear.

Seán

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Hi Sean, hope you’re great
What would be a practical representation of the two point loads subjected on this beam?
Also what are some practical representations of point loads on other RC elements (such as slabs, columns, staircases) and how are these loads transferred from one element to another? (for example slabs > beams > columns > footing/foundation).

Please let me know if you might have not understood the question properly. I acknowledge that I have asked quite a lot at once.
Thanks.

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Hi @Jomo_Ndirangu,

Point loads onto RC elements like beams and slabs can come from a variety of sources, but I guess the most obvious would be from other RC column elements, particularly when the beam or stab is acting as a transfer structure. But we can also have point loads applied from things that are resting on the beam/slab…the obvious example of this that comes to mind would be plant or other heavy equipment that will be installed (often onto the roof of a building).

Let me know if I haven’t answered your question.

Seán