Fresh Concrete Pressure Calculator
Enter pour height and fresh concrete unit weight to compute the maximum formwork lateral pressure (kPa) and total horizontal thrust per meter (kN/m), aiding formwork support design.
Input Data
Results
At a glance:Fresh concrete is treated as a fluid: lateral pressure increases linearly with depth, p(y) = γ×y, max at bottom = γ×h (kPa = kN/m²). Total horizontal thrust per meter of wall width is the triangular-distribution area = ½×γ×h² (kN/m). This calculator uses the hydrostatic approximation, ignoring vibration, pumping dynamic pressure, and strength gain during setting; actual formwork design must follow relevant codes (e.g. ACI or BS EN) and consider pour rate.
Formula
Bottom pressure = γ × h
Thrust per meter = ½ × γ × h²
$$p = \gamma h$$$$F = \frac{1}{2}\gamma h^2$$How to Use
- Enter the pour height (m).
- Confirm the fresh concrete unit weight (kN/m³).
- The system outputs the bottom max lateral pressure and thrust per meter.
Case Studies
3 m wall formwork
h3, γ24.
Bottom pressure 72 kPa; thrust 108 kN/m per meter.
5 m column formwork
h5, γ24.
Bottom pressure 120 kPa; thrust 300 kN/m per meter.
FAQ
Why treat concrete as a fluid?
Unset concrete is fluid and exerts liquid-like lateral pressure on formwork, so the early-stage estimate uses hydrostatics.
How far from code formulas?
Codes (e.g. ACI 347) add pour rate and temperature caps; this calculator is a conservative fluid approximation, and actual pressure higher up may be lower due to setting.
Related Tools
References
Content review: Calculatorism Construction Team. Results are for reference only; please refer to the relevant authorities for the official figures.