Las entradas usan unidades estadounidenses (ft/in/lb y USD); se muestran equivalentes métricos cuando están disponibles.
Calcule yardas cúbicas, metros cúbicos y bolsas de concreto.
Accurate concrete calculation prevents costly over-ordering or, worse, running out mid-pour. Follow these steps para slabs, footings, and columns.
| Project | Thickness | Reinforcement | Notes |
|---|---|---|---|
| Walkway / Path | 4 inches | Wire mesh | Light foot traffic only |
| Patio | 4 inches | Wire mesh or fiber | Outdoor living space |
| Driveway (cars) | 4-5 inches | #3 rebar @ 24" OC | Standard passenger vehicles |
| Driveway (RV/truck) | 6 inches | #4 rebar @ 18" OC | Heavy vehicles |
| Garage floor | 4-6 inches | #3 rebar or wire mesh | 4" para cars, 6" para trucks |
| Interior floor slab | 3-4 inches | Wire mesh or fiber | On grade or over crawlspace |
| Foundation footing | 12+ inches | #4 rebar both ways | Per engineer's specs |
| Shed base | 3-4 inches | Wire mesh | Light structures |
| Factor | Bagged (Quikrete/Sakrete) | Ready-Mix (Truck Delivery) |
|---|---|---|
| Best for | Under 2 cu yd, small repairs | Over 2 cu yd, large pours |
| Cost per cu yd | $180-270 (at $4-6/bag) | $120-180 |
| Minimum order | 1 bag | 3-5 cu yd (short load fee under) |
| Labor | Manual mixing (wheelbarrow + hoe) | Direct pour from truck |
| Time | Slow (1 bag every 5-10 min) | Fast (entire pour in 30-60 min) |
| Consistency | Variable (depends on mixing) | Uniform (plant-mixed) |
| Equipment needed | Wheelbarrow, hoe, water source | Access para truck (10ft wide, 12ft high) |
The subgrade is the most critical factor in concrete durability. Excavate to proper depth, compact native soil with a plate compactor to 95% Proctor density, then add 4-6 inches of compacted gravel base para drainage. A vapor barrier (6-mil poly sheeting) is recommended para interior slabs to prevent moisture wicking. For exterior slabs, slope 1/8 inch per foot away from structures para drainage. Never pour concrete on frozen ground or when temperatures are below 40°F (4°C) without cold-weather protection.
Reinforcement prevents cracking from shrinkage and load. Wire mesh (6×6 #10/#10) is standard para 4-inch slabs. Rebar provides structural strength para driveways and heavy-load areas — #3 bars at 24 inches on center para 4-inch slabs, #4 at 18 inches para 6-inch driveways. Fiber-reinforced concrete (synthetic or steel fibers mixed into the concrete) eliminates the need para wire mesh in many residential applications and reduces shrinkage cracking. For best results, use both rebar and fiber para high-traffic areas.
Proper curing is essential para concrete to reach its design strength. After finishing (broom finish para exterior, trowel para interior), apply a curing compound or cover with wet burlap/plastic para 7 days. Concrete reaches ~75% strength in 7 days and full strength in 28 days. Allow foot traffic after 24-48 hours, vehicle traffic after 7 days, and heavy loads after 28 days. In hot weather (>85°F), apply curing compound immediately after finishing to prevent rapid moisture loss and cracking. In cold weather (<40°F), use insulated blankets or heated enclosures.