materials needed for making (lego type) concreate blocks

[lord mud of the flyes]

So say I start with a 45 gallon oil drum and want to fill it

How much sand cement and hard core and water would I need (making them somewhere with no water supply)

Thanks

[JohnMo]

Pretty sure the there are volume calculators online, do a Google search, for volumetric concrete calculation.

 

Not sure you would be adding hard core, just sand, cement and gravel, plus water. Ratio depends on strength grade of concrete required.

Edited Friday at 14:38 by JohnMo

[Roundtuit]

Google suggests:

[JohnMo]

Or just go your local concrete supplier and get a 'mix on demand' truck, to fill your moulds. You tell the person in control of the truck, slump needed, strength grade, aggregate size, he will do the rest, either dump straight to mould or via wheel barrow. 30 mins to an hour later, he will be off to the next job. Zero heavy lifting needed, no guess work or arsing about

[SteamyTea]

There will be quite a bit of air in the mixture, and over time it will shrink a bit.

Some things are not worth modelling, just get some materials in and start mixing.

 

Now I assume you are thinking of a standard imperial oil drum (45 imp gal) as opposed to a US oil drum (55 US gal, or 46 imp gal).

Or somewhere between 205 and 208 litres. 

I used to listen to 208 MW when I lived in France, was one of the only English speaking music channels we could get.

[JohnMo]

1 hour ago, SteamyTea said:

I used to listen to 208 MW when I lived in France, was one of the only English speaking music channels we could get

That's a huge tangent 

[SteamyTea]

28 minutes ago, JohnMo said:

That's a huge tangent 

Been a long day behind the wiper blades.

[saveasteading]

8 hours ago, lord mud of the flyes said:

drum and want to fill it

Why?   The purpose will affect the mix.

Does it need to be strong?

[lord mud of the flyes]

On 14/11/2025 at 14:36, JohnMo said:

Pretty sure the there are volume calculators online, do a Google search, for volumetric concrete calculation.

 

Not sure you would be adding hard core, just sand, cement and gravel, plus water. Ratio depends on strength grade of concrete required.

There is no point in doing a google if you dont know what you are doing! BTW Im cementing fence bolts to it to hang a fence

[lord mud of the flyes]

On 14/11/2025 at 16:01, Roundtuit said:

Google suggests:

Are you saying that the above ratio is for 1 cubic meter. or for 205L/ 45 gallon which what i am using?

[lord mud of the flyes]

On 14/11/2025 at 16:33, JohnMo said:

Or just go your local concrete supplier and get a 'mix on demand' truck, to fill your moulds. You tell the person in control of the truck, slump needed, strength grade, aggregate size, he will do the rest, either dump straight to mould or via wheel barrow. 30 mins to an hour later, he will be off to the next job. Zero heavy lifting needed, no guess work or arsing about

Wow! you recon they will come out just to fill 2x 45 gallon drums, I wonder what the cost of that will be

[lord mud of the flyes]

On 14/11/2025 at 18:18, SteamyTea said:

 

 

Now I assume you are thinking of a standard imperial oil drum (45 imp gal) as opposed to a US oil drum (55 US gal, or 46 imp gal).

Or somewhere between 205 and 208 litres. 

 

Yes that right, english imperial 45 gallon/ 205 litres

[lord mud of the flyes]

On 14/11/2025 at 23:06, saveasteading said:

Why?   The purpose will affect the mix.

Does it need to be strong?

It needs to be strong enough to hold a gate post and strong enough to bond to a gate post fitting

[saveasteading]

8 hours ago, lord mud of the flyes said:

strong enough to hold a gate post

So nothing special.

And it will be an oil drum filled with concrete?

You could add bigger stones, half bricks and it would be fine.

[JohnMo]

9 hours ago, lord mud of the flyes said:

cementing fence bolts to it to hang a fence

Bolts assume is fence posts?

 

What has fence posts got to with concrete Lego blocks, they are about 2m³ each.

 

Just use postcrete, get it by the bag from any DIY outlet or builders merchants. Not sure why you need an oil drum of concrete to secure a fence post.

 

Maybe you need to expand on what your doing to get better answers, sorry we can only go on what you write down.

[torre]

I think we need a fuller picture re your 'Lego" plans.

 

I'm struggling to think of any scenario where it isn't easier to either take sufficient water to site or have it delivered, and build with standard materials.

 

You'll struggle to cast interlocking blocks consistently enough to build with them.