Ready-mix concrete
Also called: ready-mixed concrete, truck concrete, delivered concrete
Concrete batched at a plant to a specified strength and slump and delivered by truck, sold by the cubic yard ($170–$220) with fees for small loads and waiting time. The practical choice for any slab over about 1.5 cubic yards; bagged mix covers smaller pours.
Ordering ready-mix means telling the plant four things: the volume in cubic yards (length × width × depth in feet ÷ 27, plus 10%), the strength (3,000 psi for patios, 3,500–4,000 for garages and driveways), the slump (4–5 inches for a slab — stiffer is stronger, wetter is easier to place), and whether it should be air-entrained, which it should be anywhere the slab will freeze. Fiber, accelerators for cold weather and retarders for hot are cheap add-ons.
The truck gives you a set unloading window, usually 5–10 minutes per yard, and charges $1.50–$3 a minute beyond it. Orders under 4–6 yards carry a short-load fee. The concrete is workable for about 90 minutes after batching, less in heat, and the clock starts at the plant, not at your forms.
Bagged mix (60 or 80 lb) is the alternative for small pours: about 45 80-lb bags per cubic yard, mixed in a rented drum mixer. It costs about the same per yard as a short load and lets you pour in sections at your own pace, which is why it suits a 10×10 pad and not a 20×20 garage floor.