Ideas needed

[howardm]

Hi,
I am seeking inspiration for my settling tank project/stream diversion.
The tank will be 3metres diameter x 1 metre high sunk fully into the ground.
The hole has been dug.

I would like to cast it in place piecemeal because of access problems.
Looking for a clever way to make circular formwork.

My initial idea was to fully build the wall dry with hollow blocks, then pour cement into
the holes. Idea dashed by the usual Aberdeen unavailability/massive transport costs.

thx
Howard

 

[sparkysy]

Hi Howard
I'm assuming this will be all concrete when finished! The way I've seen it done is with thin ply bent round with ply again cut to make the formers and fixed to the opposite side usually in 3/4 sections so it can be removed once the concrete is set! Cheap and easy to make up hope this helps!
Sy

 

[captain-destructo]

cast the base and put some starter bars in ready for the walls
when makeing the shuttering for the inside just remember you have to get it back out of there
the outside if its going to be covered up and never seen you could always just leave it in situe
you can get a proper release oil for the ply so the concrete dont stick to it but people have just used red diesel in the past
if you are not casting the wall in one go mix up a little slurry cement and water and put that inbefore your second layer of concrete it will help prevent leaks and help the diferent layers concrete bond to each other

on a diferent note i saw a water tank that was made using hessian sacks filled with concrete and just stacked like bricks and the inside was rendered with a waterproof render

 

[howardm]

Thanks men,
I wanted to avoid the bother of shuttering.
I particularly like the sacks idea, but my OCD would struggle with it (not neat enough).
So, my options are, to make a mould and make my own blocks with holes in, or the sacks route.
How do I mix lightweight cement for blocks.?
Howard

 

[Rig Pig]

What about using a stock tank?

 

[fixerupper]

Yes, I think if you don't want to use shuttering ,pour a good level base and buy a plastic tank.you can concrete in in the ground if you want to. I just bought a plastic 3000 ltr enclosed tank to water my vegetables and grapes for 350 euros ...jeff..

 

[AndyStobbs]

Make it in engineering brick?

 

[fixerupper]

Per square meter concrete is cheaper than brick or block,fero concrete and a coat of waterproof render is more likely to be watertite. If you pour the wall in one go ....but with all these transporting the heavy stuff to the site is time consuming and expensive ... what about a precast manhole ring on a concrete base ,then backfilled with leanmix and earth,two coats of render with a waterproofing additive bingo job done....jeff...

 

[howardm]

The manhole ring was an early idea for me, guess what, Keyline wanted a fortune for transporting "only one ring".!
The hessian sacks are still in the lead.

 

[fixerupper]

Can you get the sand ,stone , sacks, cement and water / or readymix truck near to site? filling and transporting 100 or more hessian sacks full of concrete is a labour intensive project...jeff...

 

[Bobtail4x4]

how about the farmers favourite? straw bales wrapped in polythene.
another poly sheet and sand to take up any gaps,

once cast it will all take down,

 

[gaz1]

take a look at a septic tank there dear thoe but because your burying it you need to consider more than your thinking of access and keeping vehicles of it

https://www.google.com/search?q=sep...s.com%2Fseptic-tank-installation%2F;1600;1200

dont forget your rebars either in walls and base and also the top also a lid can be made seperatly

 

[dippy]

Pity you have dug your hole, because you could have just dug a circular trench and fillef it with concrete with rebar knocked in. When set, dig center out and do your base. Job done

 

[Rudi McAnichal]

Ferro-cement tank. Weldmesh ring + layers of chicken wire + sand-cement mortar. Lots of published instructions on DIY construction.

Curved corrugated steel panels. Pig ark sheets are advertised at under £30 each, but usually about 2.4m diameter, so rather smaller than you are looking for. You might find a local farm scrapping a corrugated circular grain bin, or even one of the vitreous enamelled tower silos.

Clay lined lagoon. Expensive unless you have clay on site or nearby. Are you anywhere near Cruden Bay, which has (or used to have) a large brick and tile works?

Do you really want an open tank? Safety considerations - it will need fencing to keep children and animals out. If you don’t need an open tank, you can probably find a farm slurry tanker that is being scrapped because its axles/brakes/tyres are worn out.

 

[captain-destructo]

if you dont fancy the sandbag method howabout this

 

[fixerupper]

Love it, but you have to drink a lot of Coke . I can't stand the stuff.....jeff

 

[captain-destructo]

Love it, but you have to drink a lot of Coke . I can't stand the stuff.....jeff

you could always use beer or wine bottles

 

[fixerupper]

Good point, but living here wine comes in 200lt barrels not bottles ...hic...jeff...

 

[excossack]

Does it have to be concrete, could you sink in 3 x 1000l IBC Cubes and connect them up ?

 

[howardm]

Thanks for the input men,
I have decided to make my own hollow blocks which will have an 18 degree sides in plan.
That's 45 blocks, cast one per evening, job done end august.

The idea is that my part-time stream flows into this tank, then swirls around, dropping all sediments to the bottom.
The water (rubbish removed) rises up to the top of a vertical central pipe 800mm high inside the tank.
Then falls into the pipe, flowing 120 metres underground into the farmer's drainage ditch.
This hopefully stops my field turning into marshland during rainy spells, and we can use it for something.
I quite fancy getting myself an classic massey furguson and plough to play with.

thx
Howard