This document discusses concrete pumps and the properties of concrete suitable for pumping. It describes how piston pumps work, with a piston moving concrete from the hopper to the delivery valve. It also describes squeeze type concrete pumps, which use rotating blades and rollers to move concrete through a flexible pipe. Concrete pumps are advantageous when concrete must be transported long distances or to inaccessible areas. Proper concrete for pumping has a slump of 5.7-10 cm, water-cement ratio of 0.5-0.65, and uses well-graded aggregate under 20mm in size.

1. Prepared by
Prof. Ashish Makwana
Civil Engineering Dept. - MEFGI
1Prof. Ashish Makwana

2. PRESENTATION
OUTLINE…
• Piston pumps
• Squeeze type concrete pump
• Advantages of concrete pump Transportation
• Properties of concrete to be pumped
2Prof. Ashish Makwana

3. 1. Piston pumps:
• After mixing the concrete, it is filled into a hopper
and pump started.
• During the suction stroke, the inlet valve is
opened and the delivery valve remains closed.
• The diameter of the piston is some what less
than the diameter of the cylinder.
• At the working end of the piston, rubber cups are
attached, which check the wastage in the
cylinder. At the other end, this piston works in
bushes.
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4. • These bushes are lubricated by the water
flowing through empty space between the
cylinder and the piston.
• This water also dissolves the cement paste
leaching through rubber cups, reducing the
danger of setting the cement paste.
• In this way the pump is kept safe from damage.
• The whole assembly is set in such a way that
every part of it can be opened, inspected, and
repaired as per need.
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5. Fig. Concrete pumps
(a)
(b)
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6. Capacity:
• Usually concrete can be pumped along a
straight and level pipe line for a distance of 300
to 450 m and upto 40 m vertical height using a
single pump.
• Any rise of 30 cm is equivalent to 2.4 m on the
level ground and a right angled bend is
equivalent to about 12 m length.
• Hence, for a 22.5 ̊ bend 3 m and for a 90̊ bend
12 m horizontal line should be reduced.
• No sharp bends should be attached in a
concrete pipe line.
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7. • In between bends straight pipe should be
attached.
• The size of pipe may vary from 11.25 to 20 cm
inside diameter
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8. 2. Squeeze type concrete pump:
• This pump was developed in USA in 1963.
• In this pump, concrete placed in a collecting
hopper is fed into the flexible pipe by the rotating
blades.
• The flexible pipe is connected to the pumping
chamber,
• In the pumping chamber a vacuum of about 600
mm of mercury is created.
• This vacuum ensures the shape of pipe
cylindrical except when squeezed by the roller.
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9. • This condition ensures the continuous flow of
concrete.
• Two rotating rollers progressively squeeze the
flexible pipe and move the concrete into the
delivery pipe.
• These pumps are lorry mounted and the
concrete is delivered through a folding boom.
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10. Advantages of concrete pump Transportation:
• At congested sites where mixing plant can not
be taken close to the point of placing the
concrete.
• At sites where stacking of aggregate is not
possible due to non availability of space.
• By this method, concrete can be delivered to
points over a wide area, otherwise not easily
accessible.
• This method of concrete transportation has been
found very useful for tunnel lining, large mass
concrete structures and densely reinforced
concrete structures etc.
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11. • This method of concrete transport is more
economical where large quantities of concrete
are required.
• Pumped concrete is free from segregation.
• In this method, concrete can be put directly from
the mixer to the formwork, avoiding the double
handling.
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12. Properties of concrete to be pumped:
• The concrete should neither be too wet nor too
dry. The slump may vary from 5.7 cm to 10 cm.
• Cement aggregate ratio should not be more than
1:6.
• Water cement ratio may vary from 0.5 to 0.65.
• A mix proportion of 1:2:4 has been found ideal
for this concrete.
• Well graded aggregate should be used for
pumped concrete.
• Light weight aggregate should not be used for
this concrete.
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13. • Maximum size of aggregate for this concrete
should be 20 mm.
• The optimum amount of fine aggregate should
be between 35 to 40% and the material finer
than 300 micron should be between 15 to 20%.
3.0% material should pass the 150 micron sieve.
• The quantity of fine particles (cement and sand)
passing through 300 micron should be 350 to
400 kg/cu.m.
• The slump of pumpable concrete should be 7.5
cm and the diameter of the pipe line should be 3
to 4 times the size of the maximum aggregate.
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