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Posted: Mon Apr 07, 2008 7:57 am
by Ted
I have been working a a power station recently and have been building various areas for them to clean oil drums and avoid fuel spillage.

Anyway I have just started on an area for them to store oil drums and was given an engineer's plan as to how to build it. They require a 15m x 5m slab with a wall around it to store drums with a drain and tank so that if a drum leaks all the oil is collected in the tank. As a drum is 210 litres in capacity the wall around the slab needs to be fairly strong as a full drum might roll down the fall towards the drain and smash in to the wall.

Anyway on the other areas I have built I did a 20cm thick wall that was 50 cm high with four runs of 10mm rebar in it.

On this one the engineer told me to reduce the thickness to 15cm. Meanwhile the height of the wall on this one is 60cm. I was told to not bother with a foundation and just dig a 15cm trench and pour the wall straight in to that and only to put one length of rebar in it 5 cm down from the wall head.

I said that I thought this was a pile of crap but was ensured it would be fine. Anyway, the power station site superviser spotted us building this wall and understandably in my view went mad. He couldn't believe there was no foundation and just one rebar. I showed him the plan ad laid the blame on the engineer and extracted myself from the situation.

Anyway so today we are going to jackhammer it all out whilst we await a new design from the engineer.

But what is the minimum thickness you would pour a concrete wall of 60cm in height and what is the minimum amount of rebar you would incorporate and where would you put it within the wall?

Posted: Mon Apr 07, 2008 8:21 am
by matt h
THIS IS A QUESTION FOR STRUCTURAL ENGINEER, BUT WOULD SUGGEST 4 LENGTH 16 MM REBAR IN FOUND WITH 10 MM REBAR IN COLUMNS OF FOUR UPRIGHTS WITH MESH ENSURING 50MM COVER, BUT THEN i WOULD ALWAYS DO AN OVER KILL!:D

Posted: Mon Apr 07, 2008 8:28 am
by Ted
Unfortunately engineers here, IME, seem to work out what is necessary and then dvide it by three, four or five to work out what they will specify.

Unless it is that if you study civil or structural engineering at the University of Bangalore or somewhere you use a completely different set of text books to what a student would leearn from at a UK, European or US university.

Posted: Tue Apr 08, 2008 6:06 am
by seanandruby
The wall needs to be incorporated into the slab to ensure it is leak proof Slab, kicker etc; Starter bars at 200ml centres should be sufficient.