MULTIQUIP MAYCO Series Operation Manual page 27

WARNING
If you repeatedly increase speed and try to force your
pump to push through blockages due to separation of
material in the hose or manifold, you will soon have
breakdowns and costly repairs which are not covered
under warranty.
If a blockage occurs, find where it is and clear it before
further pumping. DO NOT increase the engine speed
to clear the blockage. Increasing the engine speed will
only compound the problem.
WARNING
It will be necessary at times to move your pump from
one job site location to another. Before moving the
pump, make sure to pump the remaining concrete out
of the hopper. Moving the pump with a full hopper of
concrete can cause severe damage or bending of the
axle and axle springs, excess strain and pressure on
the hub and bearing assembly.
NEW PUMPS
All new pumps are "water pressure tested " at the factory
before shipment. This procedure permits a thorough
inspection of the entire drive system and valving under
simulated full load conditions.
The pump owner can do the same by attaching an adaptor
couple to the end of the discharge cone; e.g., the use of
a standard 2 in. pipe cap with a 3/8 in. hole drilled in the
center, screwed on to the end of the hinged cone or reducer
at the pump.
Fill the hopper with water after making sure that all sand
and rock have been removed from the manifold. Operate the
pump at full throttle and the 3/8 in. diameter hole restriction
will create sufficient back-pressure to make a thorough
inspection of all moving parts.
PUMPING TIPS
1. The effects of heat and excessive time on concrete:
Hot concrete, commonly referred to as a hot load, is
concrete that has been in the redi-mix truck in excess
of 2 to 3 hours. On a hot day, this amount of time is
even less. A brief explanation of why heat and time
affect concrete:
MAYCO C30HDGA CONCRETE PUMP • OPERATION MANUAL — REV. #1 (09/09/19) — PAGE 27
Concrete starts setting by drying up through a chemical
reaction. The catalyst to this reaction is heat. When
pumping a hot load, it is important to remember that
when you have to stop pumping for any reason, add
water to the concrete in the hopper and hand mix and
move concrete in the hose every 5 minutes. If the shut
down time becomes too long, wash out immediately.
2. ADMIXTURES
Remixtures that are designed into the concrete mix by
the redi-mix company or an architectural engineering
company. This section lists common admixtures and
a brief explanation of their functions:
a. Pozzolith 300 – or the equivalent acts as a water
retarder and a lubricant. On a lean mix, long
pushes, stiff mixes, and vertical pushes, Pozzolith
300R helps pumpability.
b. MBVR – air entraining, acts as a lubricant.
c. Calcium Chloride – commonly referred to as C.C.,
is used as an accelerator. When pumping a load
with calcium chloride, it is recommended that you
wash out if the waiting time between delivery trucks
becomes too long.
d. Super Plasticizers – acts as an accelerator.
The concrete will look very wet after the super
plasticizer is added, but will begin to set up very
fast. Wash out immediately if you do not have a
truck waiting. Super plasticizers are used mainly
on commercial jobs.
e. Red Label – acts as a water retarder and an
accelerator. Red label will be used mainly on
commercial jobs.
f. Fly Ash – is used to help increase the strength of
the concrete and decrease the cement content per
yard. This is one of the most common admixtures
used.
NOTICE
All admixtures will be shown on the redi-mix concrete
ticket. Before starting the pumping job, ask the driver
of the redi-mix truck to see the concrete ticket and note
the admixtures that exist and take the proper action.
OPERATION