Proportion of water to mortar and concrete mixes

[Tricky Dicky]

The instructions with my concrete mixer recommend adding the water first to prevent the aggregate sticking to the sides of the drum. The trouble is I have ended up with some sloppy mixes particularly small mortar mixes and al though I have added more aggregate to get the mix right I have ended up wit h more mix than I needed. I have not been able to find any info on the prop ortions of water, I know it can vary due to how wet the sand is already but a ball park figure would help?

Richard

[T i m]

On this subject ... What type of sand (if any) and ratio of cement (and what kind) would you typically use if casting / forming a garden planter?

Cheers, T i m

[T i m]

A bit vague I accept.

See if this puts more detail in there:

I can see how that would be idea for something chunky you were going to cast but for the 'poured' process shown above, I'm thinking it would be too lumpy?

Didn't I read here possibly something about some types of cement having fibers in it to make it stronger when used with just fine sand or somesuch?

Cheers, T i m

[ARW]

You read the instructions??? Good God man. What's wrong with you? ;-)

I would say Jim has it about right. Add some water, less than you need and add the rest later.

That's the way I have to do it.

[tabbypurr]

plastic fibres increase tensile strength greatly, which is what you need to stop breakage of planters. You can buy the fibres, or just stick a bit of synthetic carpet through a shredder.

NT

[T i m]

So, if I understand it correctly 'cement' is really only the glue that binds the aggregate together so what would I use to do the round planter shown in the video?

So would that become the only binder in with straight cement or would that be with a (say) sharp sand? The slurry shown on the video looked too fluid to be sharp so could it be soft or even silver sand etc?

;-)

Cheers, T i m

[tabbypurr]

Fibres are added to the usual sand/cement mix at somewhere around 1%

NT

[John Rumm]

That looks like they are using a dryish "building" or "soft" sand... The "concrete" looks like a fairly strong mix of cement and the same sand.

Yup you can add fibres - they give extra tensile strength which is handy for applications like that.