What makes a concrete mix hard to pump?

Stiff low-slump mixes, large or angular aggregate, and small pipe diameters all raise friction sharply. A wetter mix with rounded aggregate in larger pipe pumps with much lower line pressure for the same distance.

How is vertical lift handled?

Lifting fresh concrete adds static head of about 0.235 bar for every meter of rise, on top of friction. A tall pour can demand more pressure for the lift than for the entire horizontal run, so vertical distance matters a lot.

Why do bends add pressure loss?

Each direction change forces the concrete column to redirect, which behaves like extra pipe length. The tool adds roughly three meters of equivalent pipe per 90 degree bend, so a line with many bends loses noticeably more pressure.

Is this exact enough to size a pump?

It is a planning estimate that captures the right trends and magnitudes. For a critical or marginal pour, confirm against the pump manufacturer's pressure-versus-distance chart and the concrete supplier's pumpability data.

What is a typical pump rating?

Trailer pumps commonly develop 70 to 130 bar, while large boom pumps can exceed 200 bar. Always leave margin above the calculated requirement for pipe wear, mix variation, and to keep output up at the end of a long run.

Concrete Pump Friction Loss Calculator

Before a pour, you need to know whether your pump can actually push the mix to where it has to go. This calculator estimates the line pressure required by combining horizontal friction, bend losses, and the static head of lifting fresh concrete, then compares it against your pump’s rated pressure.

How it works

Total required pressure is the sum of three parts:

friction  = friction_gradient (bar/m) × horizontal_run
bends     = friction_gradient × (3 m per 90° bend × number_of_bends)
static    = 0.2354 bar/m × vertical_lift
total     = friction + bends + static

The friction gradient rises for stiffer low-slump mixes, larger aggregate, and smaller pipe. The static term comes from the density of fresh concrete, about 2400 kg/m³, which adds roughly 0.235 bar of head per meter of rise.

Example and tips

A 100 mm slump, 20 mm aggregate mix through 125 mm pipe over a 60 m horizontal run with 15 m of lift and four bends needs roughly 4 to 5 bar of friction plus about 3.5 bar of static head. Keep slump in the pumpable range, use the largest practical pipe, and minimize bends near the pump where pressure is highest. Always plan a generous margin: pipe wears, mixes vary batch to batch, and you want full output at the far end of the line.