How Many 150×150 mm Cubes Can I Cast from a 56 L Concrete Batch?

Quick Answer:

No fresh tests: ~16 cubes per 56 L batch
With full fresh tests (no sample reuse): ~8–9 cubes
With sensible reuse of test samples: ~12–13 cubes

Why these numbers?

Cube Volume:
- A 150×150×150 mm cube ~ 3.375 liters
Mixer capacity in this example
- Pan mixer size: 100 L; effective mixing capacity: 56 L usable concrete.
Fresh test sample needs (typical)
- Slump/flow: ~5.5 L
- Air content (pressure meter 0.25 ft³ bowl): ~7.1 L
- Density/unit weight (0.25 ft³ measure): ~7.1 L
- Temperature: negligible (usually taken in another sample)
Typical production loss allowance
- Plan 5–10% for pan residue, tools, trimming, and handling.

Scenario	Test Sample Use (liters)	Loss Allowance	Calculation	Expected Cubes
No fresh tests	0.0	0%	56/3.375	16
No fresh tests	0.0	10%	(56×0.90)/3.375	14-15
Full tests, no reuse (slump + air + density)	20.5	10%	(56×0.90−20.5)/3.375	8-9
Full tests, no reuse	20.5	5%	(56×0.95−20.5)/3.375	9-10
Full tests, sensible reuse (reuse density measure for temp; pour slump & density into molds; only air test discarded)	7.6	10%	(56×0.90−7.6)/3.375	12-13
Only slump + temperature	5.5	10%	(56×0.90−5.5)/3.375	13

Sensible reuse means you:
• Take temperature in the density measure,
• Place the slump and density samples into molds instead of discarding,
• Discard only the air-content sample (cannot be reused).