Expansion joints in external RC stair on grade

[nivoo_boss]

Hey everyone!

So I'm designing a low concrete stairs on grade (total height of about 320 mm) with 3 risers. It's relatively long though, more than 20 m. Can you give me some advice on what the spacing of expansion joints should be?

It's located in Estonia. So frost heave is a question as well. Below is a plan view and a section from the architectural model.

 

[GeorgeTheCivilEngineer]

Do you mean expansion joint, construction joint or control/contraction joint ?

I wouldn't have thought an expansion joint would be necessary. Control joints on a 1:2 ration for the width of the slab. and wherever it needs separation to other structures.

Heave can only be mitigated with joints, not controlled by it - that is down to the sub-base and anti-heave precautions.

 

[nivoo_boss]

Sorry, I don't know the proper word for it in English. I mean a joint to control cracks better to shrinkage or expansion.