At least here in the U.S., the minimum ready-mix (delivered in a truck) is about 2 cubic yards. If you only have need for a small amount, you can get cement in a bag from your local DIY (at least here in the U.S.) It's all ixed up with the sand, garvel and cement, you just add water. There's about a cubic foot per bag... it's relatively inexpensive, but heavy... maybe 60 pounds per bag. You can get several varieties... such as quick set and hydraulic cement...