CONCRETE · FIELD TOOL
Beam concrete = span × width × depth. Measure only the part below the slab if the slab is measured separately: a 300 × 600 mm beam under a 150 mm slab counts 450 mm deep, so a 6 m beam is 0.81 m³. Six of them need 4.86 m³ (5.10 m³ with 5%).
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Behind this panel: an example with the default sizes.
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| Per beam | 0.810 m³ |
| Depth counted | 450 mm |
| Order (rounded to 0.5 m³) | 5.50 m³ |
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Depth counted = D − t_slab (below slab) or D (full depth)
Volume = span × b × depth counted × nSix beams 300 × 600 mm, 6 m clear span, 150 mm slab, below-slab only:
| Beam b × D | Full depth | Below a 150 mm slab |
|---|---|---|
| 230 × 450 mm | 0.104 m³ | 0.069 m³ |
| 300 × 600 mm | 0.180 m³ | 0.135 m³ |
| 300 × 750 mm | 0.225 m³ | 0.180 m³ |
| 400 × 900 mm | 0.360 m³ | 0.300 m³ |
Multiply the clear span by the beam width and depth. If the slab is poured with the beam and measured as a full slab, count only the depth below the slab to avoid double counting.
Clear span between column faces, when columns are measured to the underside of the beam. Use centre-to-centre only if columns stop at the slab soffit in your take-off method.
Width × depth. A 300 × 600 mm beam is 0.18 m³ per metre full depth, or 0.135 m³ per metre below a 150 mm slab.