Stainless steel reinforcing bar

[NJonesUK]

I'm looking at a swimming pool design in the UK and the architect wants the steps into the pool to be built into the concrete pool wall.

There is a requirement for a minimum cover to reinforcement in swimming pools to the British Design codes of 40mm but if we use stainless steel reinforcement in the step details can we reduce the requirement for cover? If so where is there guidance for this? I've had a really good look and I'm coming up short. If there is no specific guidance has anyone got any experience with stainless steel reinforcement in corrosive environments?

The architect wants to detail steps that are 60mm deep overall (they claim it is a detail that they have used , thus the maximum cover I could likely obtain is about 25mm, significantly less than the 40mm spec'd in BS8110.

Any comments would be graciously accepted.

Best regards,

Nick

 

[NJonesUK]

Oh and before I forget, to all the Yanks, have a great Independence Day.

 

[countervail]

We have done steps set into the wall, we normally detail a pocket and keep the cover as 40mm.

I guess it depends on the step depth, width etc. but unless its something unusual you should be ok with normal rebar.

 

[hokie66]

A detail might help. I am having trouble picturing what you mean by steps built into the wall which are 60 mm deep.

 

[NJonesUK]

Detail attached, does that help?

 

[countervail]

Ahh I see

I don't know of any specific guidance for cover with stainless steel bars in pools (normally we work to BS8110 in mild steel) but I would imagine that stainless steel bars with 25mm cover would be fine (as stainless steel exposed directly to pool water is fine on its own).

I suppose tile and grout thinness has already been taken into account and you don't have to reduce the 60mm still further?

 

[NJonesUK]

Correct, countervail!

I found some guidance on the use of stainless steel rebar eventually but it doesn't provide any numerical answers. Just that 'you can probably reduce cover if the workmanship shouldn't be a problem' or words to that effect.

 

[racookpe1978]

150 mm (6 inch fer us colonial types!) is a very, very deeply recessed step.

Even a man's foot 300 mm long would not be able to "insert his toe" 150 mm deep into a recess that small top to bottom, especially not while climbing. Why do they want that much depth in the recess?

 

[hokie66]

Poor detail, no matter what the architect says. You won't be able to consolidate the concrete in that 60 x 150 section. Suggest you just leave out the whole 150 deep section, and make the steps out of something else, maybe stainless steps bolted to the concrete with stainless anchors.

 

[NJonesUK]

Architect isn't shifting on this one, apparently.. He insists that the detail has been used before and that it is perfectly workable. I, like you chaps, have my reservations.

Cheers for your views, chaps. Much appreciated.

 

[hokie66]

I would call his bluff and go and visit the pool where the detail is said to have been used. You can't always trust an architect.

 

[slickdeals]

Is the pool, that the architect is referring to, conventionally placed concrete or pneumatically placed (shotcrete)?

 

[NJonesUK]

Conventional.

 

[MiketheEngineer]

Keep the cover - stainless can "rust" believe it or not!!

Or shall I say oxidize??