Phần hướng dẫn bên dưới chưa có bằng tiếng Việt nên được hiển thị bằng tiếng Anh. Bản thân máy tính đã được dịch đầy đủ.
Cách sử dụng máy tính này
- Choose US or metric units and the shape (slab/footing or round column).
- Enter the dimensions. Slab thickness is in inches or centimeters; a typical patio or walkway slab is 4 in (10 cm).
- Enter how many identical pours you need and a waste allowance (5–10% is common for spillage and uneven ground).
Công thức
Volume is length × width × thickness for slabs, and π × radius² × height for columns. Bag counts divide the total by the typical yield of each bag size.
Slab: V = L × W × T
Column: V = π × (D/2)² × H
1 yd³ = 27 ft³ = 0.7646 m³
80 lb bag ≈ 0.6 ft³; 60 lb ≈ 0.45 ft³; 40 lb ≈ 0.3 ft³
Example
- 10 ft × 10 ft slab, 4 in (0.333 ft) thick: 33.3 ft³.
- ÷ 27 = 1.23 yd³; with 10% waste ≈ 1.36 yd³.
- That's about 62 bags of 80 lb premix, so ordering ready-mix may be more practical.
Câu hỏi thường gặp
When should I order ready-mix instead of bags?
For more than about 1 cubic yard (0.75 m³), a ready-mix truck is usually cheaper and easier than mixing dozens of bags. Ask suppliers about minimum orders.
How thick should a slab be?
Patios and walkways are often 4 in (10 cm). Driveways typically use 5–6 in (12–15 cm). Follow local codes and engineer requirements for structural slabs.
Why add a waste allowance?
Subgrades are rarely perfectly flat, forms flex, and some concrete is always lost. Running short mid-pour can create a weak cold joint.