Calculator Inputs
Example Data Table
| Scenario | Cyl Ø (mm) | Stroke (mm) | SPM | Fill (%) | Mech (%) | Line (m) | Bends | Estimated Output (m³/h) |
|---|---|---|---|---|---|---|---|---|
| Slab pour, short line | 200 | 2100 | 22 | 85 | 90 | 30 | 2 | ≈ 45–55 |
| Core wall, more bends | 200 | 2100 | 20 | 80 | 88 | 60 | 6 | ≈ 30–40 |
| Elevated placement | 230 | 2100 | 18 | 82 | 90 | 50 | 4 | ≈ 28–38 |
Values are illustrative; field conditions can shift output significantly.
Formula Used
How to Use This Calculator
- Choose a method: cylinder geometry or manufacturer rated output.
- Enter cylinder and stroke data, or rated output, plus cylinders count.
- Set fill factor and mechanical efficiency based on pump condition.
- Add line length, vertical rise, and bends to estimate delivery losses.
- Use site efficiency for crew, access, and placement constraints.
- Enter pour volume to estimate total placing time, then calculate.
Concrete Pump Output Planning Guide
1) Why output estimates matter
Concrete placement is usually scheduled by cubic meters per hour, but real production depends on pump capacity, line setup, and crew flow. A realistic output estimate helps match truck arrival spacing, prevent cold joints, and avoid overworking finishers. Use this calculator to compare theoretical capacity with jobsite delivery.
2) Theoretical vs. delivered output
The cylinder-geometry method converts stroke volume and strokes per minute into a gross rate. That number is an upper bound. Intake losses, valve timing, and concrete compressibility reduce the fill factor, while wear and hydraulics reduce mechanical efficiency. Delivered output often lands 20–45% below gross when conditions are average.
3) Typical field ranges
Small line pumps commonly place 20–50 m³/h on straightforward slab pours. Medium boom pumps may reach 60–120 m³/h on favorable mixes and short, clean lines. High-rise or long lines can drop output significantly, especially when vertical rise increases pressure demand and pauses become frequent.
4) Line length, rise, and bends
Every meter of pipe adds friction, and bends add turbulence and pressure losses. Even when the pump can generate the needed pressure, higher losses tend to lower stable strokes per minute and increase stoppages. This calculator uses adjustable loss coefficients so you can model short runs, long horizontal runs, or elevated placements.
5) Mix design and slump considerations
Workability affects pumping. Harsh mixes, low paste content, oversized aggregate, or poor lubrication can reduce fill factor and cause pressure spikes. Higher slump or well-designed pumpable mixes generally improve continuity, but excessive water can compromise strength. Coordinate with the batch plant for pump-friendly gradation and admixtures.
6) Crew and logistics efficiency
Site efficiency captures the “human system”: truck positioning, chute management, hose handling, finishing pace, and rebar congestion. If trucks arrive too quickly, you waste time washing out; too slowly, you risk set and joints. Use site efficiency to reflect realistic coordination and access constraints.
7) Using the pour-time estimate
Enter total pour volume to estimate placing duration. Include a small delay per hour to represent priming, brief line moves, and cleanup. If the estimate is tight, add contingency time for line blockages, weather, or inspections. The goal is a schedule that protects quality, not just speed.
8) Quality and safety checks
Higher output is not always better. Monitor pressure, watch for segregation, and maintain safe exclusion zones around the boom and hose. Confirm formwork bracing can handle the intended placement rate. Balanced planning improves finish, reduces rework, and keeps crews safe throughout the pour.
FAQs
1) Which method should I use?
Use cylinder geometry when you know diameter, stroke, and strokes per minute. Use rated output when only manufacturer capacity is available. Geometry is better for comparing setup changes and efficiency assumptions.
2) What is a realistic fill factor?
Many pumps run near 75–90% fill in good conditions. Harsh mixes, long suction, and intermittent feeding reduce fill. Start at 85% and adjust after observing stable production on similar pours.
3) How do I choose line-loss values?
Use higher losses for long lines, tight elbows, worn pipe, or stiff mixes. Use lower losses for short, clean lines and pumpable mixes. Adjust coefficients until the model matches your observed output trends.
4) Why does vertical rise reduce output?
Vertical pumping increases pressure demand and can reduce stable stroke rate. It also amplifies the impact of pauses and priming issues. Even when pressure is sufficient, operators often slow to maintain steady flow.
5) How should I set site efficiency?
Use 70–90% for well-coordinated, accessible pours. Drop to 40–70% for congested reinforcement, long hose handling, frequent moves, or limited truck access. Site efficiency is the biggest driver of real productivity.
6) Can I use this for boom pumps and line pumps?
Yes. The physics of stroke volume and efficiency applies to both. Boom pumps often face additional pauses for repositioning and hose control, so consider slightly higher delay or lower site efficiency.
7) What should I do if the estimate seems too high?
Lower fill factor, mechanical efficiency, and site efficiency first, then increase line losses if your setup is long or complex. Validate by timing a short trial placement and updating inputs to match field reality.