Multiquip SCRUCTURAL CONCRETE PUMP ST-45HRM - Manual (Page 25)

MAYCO ST-45HRM PUMP — OPERATION & PARTS MANUAL — REV. #4 (07/16/04) — PAGE 25
ST-45 PUMP — OPERATING PROCEDURES
WARNING
Common sense tells us that if you drive a
truck into a brick wall, something is going to
be damaged. The same holds true with your
concrete pump. If you repeatedly pull the
throttle all the way out 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.
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
breakage of the axle and axle springs, excess
strain and pressure on the hub and bearing assembly.
WARNING
Pumping Tips
The effects of heat and excessive time on concrete:
7. 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:
8. 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.
Admixtures:
9. 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 explana-
tion 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.
All admixtures will be shown on the
redi-mix concrete ticket. Before start-
ing 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.
10. When pumping long distance or pumping stiff mixes, you can
expect a drop in volume compared to shorter lines and wetter
mixes due to the change in valve efficiency or cavitation.
11. Leaking manifold seals or hose coupling gaskets which leak
water can cause separation and subsequent jamming at that
point.
NOTE
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.
Priming the Pump and Delivery System with Slurry
12. It is CRITICAL to the successful operation of a concrete
pump that the manifold and all delivery hose, pipe and
elbows are coated with a film of lubrication BEFORE you
attempt to pump concrete. Failure to properly prepare the
pump and system will result in a “dry pack” of concrete,
blocking the shuttle valve tube or delivery line.
A. With the entire delivery system connected to the pump.
Except for the first hose. Pour 5 gallons of water into the
second hose and push in your clean out ball and
reconnect. This will help hold back the prime.
B. There are several things you can use for the prime. A
few examples are Cement and lime at a 50/50 mixture,
slick pac, bentonite clay.