According to ASTM C1433 and C1433M, the standard dimensions of precast concrete box culverts are as listed in the table below. You can stand them up or lay them down flat, and you can put as many as you want side by side.
| Dimensions | Thickness | ||
|---|---|---|---|
| ft x ft | mm x mm | inches | mm |
| 3 x 2 | 900 x 600 | 4 | 100 |
| 3 x 3 | 900 x 900 | 4 | 100 |
| 4 x 2 | 1200 x 600 | 5 | 125 |
| 4 x 3 | 1200 x 900 | 5 | 125 |
| 4 x 4 | 1200 x 1200 | 5 | 125 |
| 5 x 3 | 1500 x 900 | 6 | 150 |
| 5 x 4 | 1500 x 1200 | 6 | 150 |
| 5 x 5 | 1500 x 1500 | 6 | 150 |
| 6 x 3 | 1800 x 900 | 7 | 175 |
| 6 x 4 | 1800 x 1200 | 7 | 175 |
| 6 x 5 | 1800 x 1500 | 7 | 175 |
| 6 x 6 | 1800 x 1800 | 7 | 175 |
| 7 x 4 | 2100 x 1200 | 8 | 200 |
| 7 x 5 | 2100 x 1500 | 8 | 200 |
| 7 x 6 | 2100 x 1800 | 8 | 200 |
| 7 x 7 | 2100 x 2100 | 8 | 200 |
| 8 x 4 | 2400 x 1200 | 8 | 200 |
| 8 x 5 | 2400 x 1500 | 8 | 200 |
| 8 x 6 | 2400 x 1800 | 8 | 200 |
| 8 x 7 | 2400 x 2100 | 8 | 200 |
| 8 x 8 | 2400 x 2400 | 8 | 200 |
| 9 x 9 | 2700 x 1500 | 9 | 225 |
| 9 x 6 | 2700 x 1800 | 9 | 225 |
| 9 x 7 | 2700 x 2100 | 9 | 225 |
| 9 x 8 | 2700 x 2400 | 9 | 225 |
| 9 x 9 | 2700 x 2700 | 9 | 225 |
| 10 x 5 | 3000 x 1500 | 10 | 250 |
| 10 x 6 | 3000 x 1800 | 10 | 250 |
| 10 x 7 | 3000 x 2100 | 10 | 250 |
| 10 x 8 | 3000 x 2400 | 10 | 250 |
| 10 x 9 | 3000 x 2700 | 10 | 250 |
| 10 x 10 | 3000 x 3000 | 10 | 250 |
| 11 x 4 | 3300 x 1200 | 11 | 275 |
| 11 x 6 | 3300 x 1800 | 11 | 275 |
| 11 x 8 | 3300 x 2400 | 11 | 275 |
| 11 x 10 | 3300 x 3000 | 11 | 275 |
| 11 x 11 | 3300 x 3300 | 11 | 275 |
| 12 x 4 | 3600 x 1200 | 12 | 300 |
| 12 x 6 | 3600 x 1800 | 12 | 300 |
| 12 x 8 | 3600 x 2400 | 12 | 300 |
| 12 x 10 | 3600 x 3000 | 12 | 300 |
| 12 x 12 | 3600 x 3600 | 12 | 300 |
Not all manufacturers will be able to build all sizes, and some in my area can build larger sizes than this in their precast facility. Thus it is important to check with manufacturers in your area before specifying precast concrete boxes.
The factors involved in choosing concrete box culvert over other culvert types are structural capacity, depth of cover, channel geometry, and hydraulics. Often concrete boxes are chosen due to their structural strength when cover is too low or too high for corrugated steel.
Our previous article How to Design a Concrete Box Culvert presents more information about choosing concrete box sizes and structural design.
Speak Your Mind