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# 2016FallShotcreteEMag

Technical Tip
of concrete per hour. You have a trailer pump
which can exert a maximum pressure of 1100 psi
(7.6 MPa) on the concrete and you have 2 in.
(50 mm) diameter pumping line. Using only hose,
you would have 250 ft (76 m) of hose (Fig. 1)
which yields a proportional value of 750 (assuming
a 3× multiplication for hose, which varies from 3
to 5× multiplication.) Using a combination of pipe
and hose, you would have 200 ft (61 m) of pipe
followed by 50 ft (15 m) of hose (Fig. 2) yielding
a proportional value of 350. We will omit the
reducers because they are the same for both cases.
Using these proportional length values, refer
to the pumping nomograph (Fig. 3). Beginning
with the desired pumping rate of 15 yd3 (11 m3)
per hour, trace to the right until you hit the line
for the 2 in. (50 mm) pipeline size. Then trace
downward until you hit the line for your proportional
length value. Trace left from that intersection
to the line for 2.5 in. (64 mm) slump, and
then upwards to the predicted pumping pressure.
The pumping pressure with Option 1, using
only hose, will be just above 1000 psi (7 MPa),
using nearly all of the pressure available from this
Option 1—Hose Only
• 250 ft (76 m) of hose
250 ft × 3 (hose multiplier) = 750 proportional ft (230 m)
Fig. 1: Proportional length calculation, Option 1
Option 2—Steel Line and Hose
• 200 ft (61 m) of steel line
• 50 ft (15 m) of hose
200 + 50 ft × 3 (hose multiplier) = 350 proportional ft (110 m)
Fig. 2: Proportional length calculation, Option 2
pump, and approaching or exceeding the working
pressure of many widely available pumping
hoses. Adding in the resistance provided by the
line reducers near the pump or any higher multiplier
values from the hose based on using dirty
Fig. 3: Concrete pumping nomograph. Nomograph courtesy of Schwing America, Inc.
Shotcrete • Fall 2016 33

2016FallShotcreteEMag

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