Concrete mixing

[Dice_man_]

Hello, I'm currently planning a project to widen my exisiting gravel driveway. The driveway is higher than the adjacent lawn by about 1 foot so the extra section needs to be built up with hardcore and then a layer of concrete with top layer of gravel all against a retaining wall. I would like some advice here as to what thickness would be best for the hardcore and concrete layers.

Based on some advice so far I am thinking to use 6 inches of concrete (correct me if you think this is unnecessary) which would require approximately 0.5 metre cubed concrete. My question here is whether it would be feasible for me to mix this much onsite with a hired petrol powered mixer to save cost or whether I would need to order it ready mixed and delivered.

Thanks in advance for any input on these queries.

[welsh brickie]

for your driveway its best to lay 150mm of well compacted hardcore.I would suggest you hire a plate compactor to do this.
The concrete thickness should be a minimum of 100mm.
If you have redimix delivered you only have 2 hours to lay it before it begins to cure.I would suggest mixing it yourself you have more time to work it.

[Dice_man_]

Thanks for the quick response that helps me a lot. More questions I'm afraid as this is really my first building project:

I was going to do a C20 concrete mix but looking at material costs it appears cheaper to buy ballast material rather than sharp sand and gravel separately. May I ask if I use ballast instead will this be sufficient for the minumum 100mm thickness. Also what proportion of ballast vs. cement would be recommended for a driveway and/or retaining wall footing to be equivalent to C20 - would it simply be 6:1?

[welsh brickie]

6:1 is fine

[brilhoservices]

6:1 is the best