concreting on top of RSJ

30 Aug 2011
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United Kingdom

We want to make a floor on top of some RSJ, the span of each RSJ is about 1.200mm, I want to concrete over the beams to make a floor, with mesh in of course.
Do I need to treat the steel with anything?

Can I simply make a wooden shutter to flush fit with the top of the RSJ lay my re-bar and concrete a 6" slab on top.
should I or could I make a shutter around my RSJs and concrete the lot.
The RSJ's are 6"x4" there'll be a small wall on the outer beam we'll use hollow blocks there, apart from that people will only walk on the floor.


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Is the RSJ suitable for extra load that it will be carrying?
I assume the RSJ was calculated for it's existing use, not the addition of 6 inch of concrete slab and block work.
Well I don't know what your purpose is for out there in Ghana, but I can say that you don't have to treat the steel in any special way.

However, if the location means corrosion due to it getting wet will occur, getting at least a steel primer on it first will help. Better still a full paint system.
They were used for an overhead gantry operation, all i wan to do is floor it and use the space.
it's about 2.5 m wide with gaps between of 1.2m 3 of these gaps.

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You don't need to treat the steel unless it is exposed to regular damp. But as a minimum consider a coat of paint or primer

You can encase the steel, but the concrete will need sufficient cover to prevent it cracking - and probably some mesh in it as well

Your steel reinforcement in the concrete may need to be adequate to prevent shear of the slab next to the beam - so it may not be just a case of throwing some mesh into it. But it depends on what is going on with the rest of the slab - it may well be OK for just that short span
We don't have any regulations like the UK.
but for piece of mind I'd like to know if they would be ok for the job.
THanks woody.

We'll use some 14\16 mm rebar, on 2" spacers. 6x6 mesh

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