The 4h pumping of Neufahrn: Large boom team places ... - Putzmeister

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Technology · Question 6
How long do truck-mounted
concrete pumps last?
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Even Putzmeister engineers continue to
be surprised by how long truck-mounted
concrete pumps can be in service: some
machines have almost 40 years of service
under their belt.
Luckily, Putzmeister‘s Services department
employs true experts when it comes to spare
parts for old truck-mounted concrete pumps:
“Our computerised spare parts management
only began in 1983. Before then, everything
was done in our heads or was found in old
documents.”
Several times a month, we receive requests
that can only be solved by human intelligence.
One such example is the water-hydraulic
driven concrete pump B232, manufactured
in 1971. To put this machine out of
service has never crossed the mind of the
Polish entrepreneur Grzegorz Kujawski. He
regularly orders new spare parts.
What makes truck-mounted concrete
pumps grow old
Three factors determine the service life of a
truck-mounted concrete pump:
• how the machine is serviced and
maintained,
• the number of hours that it is in
operation,
• and the quantity of concrete that is
pumped.
p B / 9 years old/Poland
This water-hydraulic driven concrete pump B has been in use since 1971. Even in
008, it was still pumping a daily volume of 150 cubic metres of concrete.
According to the requirements that
Putzmeister‘s engineers are given, the
truck-mounted concrete pumps should be
able to keep working for at least 10 years.
The critical factor here is the design of the
placing boom. During pumping operations,
the boom is particularly stressed by the
load shifting. The number of load changes
is determined by the pump output and the
operating hours.
Anti-aging – past and present
In the past, designers could rely upon their
knowledge and experience and consult with
others regarding standards and regulations.
If there was any doubt, they increased the
strength of the material at heavily-used
points on the placing boom. As early as the
end of the 1970s, Putzmeister owned a test
q M 45-5/ years old/Austria
This M 45-5 worked almost 1 ,000 operating hours over 0 years before getting a
new owner.
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p M 1- / 7 years old/Cyprus
This M 1- “Triplet” that was manufactured in 198 is still in top form. For its 6th birthday in 00 , it underwent a major overhaul
and was affectionately given the name “Our favourite grandmother”, which was prominently displayed on the boom.
rig to simulate long periods of use. If the
boom passed the test, the design could go
into series production. In practice, something
became clear: The machines keep working
for considerably longer than 10 years – provided
that they are well maintained. As is
the case with the machine from Poland.
Since the beginning of the 1990s, the designers
have used finite element analysis
(FEM) to precisely calculate the stress on
the components. A screen in the software
programme shows the tension that will later
appear in the material and shows the critical
points. The design, material and material
thickness can then be optimised. Using a
new boom test rig, the engineers can simulate
years of the life-cycle of the boom at
high speed.
q M 46-5/7 years old/China
Since 00 , this M 46-5 has pumped an annual volume of 90,000 m in Shanghai!
That is three times more than the same machines in Europe.
Practical test in China
How well do the computer-optimised designs
actually work in practice? There are no machines
that are 40 years old yet. However,
there are truck-mounted concrete pumps
that have worked considerably more than
you would assume from their year of manufacture.
In China, young machines are already old.
The M 46 shown (year of manufacture:
2003) has worked non-stop since its delivery:
pumping volumes of 90,000 cubic metres
of concrete each year are the norm – at peak
times, the pumping volume increases to
up to 12,000 cubic metres of concrete each
month. By comparison: In Europe, large
boom truck-mounted concrete pumps deliver
approx. 30,000 cubic metres of concrete
each year. In terms of European machines,
this machine has already survived the required
10 years well – and it continues to
run and run and run. n
1 PM 4356 GB PM 4356 GB 1
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