Question about 1:3:6 ratio mix concrete

[Adrianlondon]

Hi all

I need an ST2 concrete mix for my floor. I believe this is a 1:3:6 ratio (please correct me if I'm wrong).

If I want to use just cement, ballast and water

1) Can I do that?
2) What would the ratio be?

As a point of interest, I need to fill an area which is 6m x 6m x 150cm




Adrian

 

[wakey77]

By my reckoning mate with an area of 6 x 6 x 150 your going to want around 5 and half metres of concrete if your going to knock that up using ballast thats approx 11 ton of ballast and around 65 bags of cement for the materials id expect to pay around £600 (west midlands prices) + delivery + mixer + sore hands and a bad back.
you could get that quantity ready mixed cheaper and some companies barrow it for you.
usually i use a gen2 on my internal floor slabs.

 

[munchingB]

metre and a half deep floor?

 

[Adrianlondon]

Sorry 150mm!!! I'm a moron sometimes!!!

Actually, it needs to be 100mm

Although I've worked it out to be 4 cubic metres I'm not sure how much ballast and cement I'd need.

 

[themiddleagedun]

A third less than Wakey said then

 

[munchingB]

3.6 cubic metres

 

[Adrianlondon]

With the figure of 3.6 cubic metres, can someone give me an idea as to how many tonnes of ballast and cement I will need (If I can use only ballast and cement).


Adrian

 

[r896neo]

Seriously buy readymix. Half will be stiff and ready to float while your still knocking your pan in mixing the rest panicking the whole time as it gets stiffer and stiffer.

1:3:6 is fine for oversite concrete only really. Certainly not for a finished floor?? Even if your having a screed on top C15 or 20 would be better

 

[Adrianlondon]

Thank you. It isn't going to be the finished floor. There will be a screed on top of it. The plans show that I need 100mm of ST2 which I believe is 1:3:6

I'm only going by what the plans state. Are the plans wrong???

 

[r896neo]

sorry my mistake ST2 appears to be C25 which would be fine