allen BDF4836B, Инструкция по безопасности и эксплуатации

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12. PAVING THIN BONDED CONCRETE OVERLAYS
It is very important that the machine has a straight and solid set
of screed rails. It is our experience that round pipe is superior to
square tubing or beam rails. We recommend 2” schedule 80 black
iron pipe used with low profile overlay adjustable screed chairs
spaced 24“ on center. The pipe is easier to align, set into screed
chairs and confirm to radius turns. If the overlay is made in several
passes a nail strip is commonly used to help maintain a straight
edge and to keep the outer edge from slumping. It is also a way
to minimize the waste of material.
Do not place material over 5
feet in front of the machine.
All vibration attachments are easily controlled on the front of the
carriage. This permits changing vibration speed to match the
requirements of the job and the depth of the mix. With the vibra -
tion properly adjusted, the attachments will make the material
more uniform, removing air pockets and voids. If your machine is
equipped with a Roller Tamper, set the finned rollers 1/2” to 3/4”
below finished grade and run between 4000 to 5500 vibrations
per minute. For maximum production every effort should be made
to control the quality and consistency of the concrete mix. Deep
holes or partial depth pockets should be filled and vibrated with
hand vibrators.
The setup time, the time it takes for the film or latex skin to form
on the surface, is 10 to 15 minutes with a normal slump of 4-1/2
to 7 inches. It is important that the finishing process be completed
within ten minutes. This will give adequate time for hand finishing
along curb edges and for the surface texturing required before the
surface film or skin forms.
Because latex modified concrete drys quickly, weather conditions
are an important paving variable. It is not recommended that latex
modified concrete be poured if the temperature exceeds 85° F
or if there is a high and constant wind. Heat and high winds will
speed up the setup time and cause serious finishing problems.
Actually, the best time to pour latex modified concrete is between
2 AM and 7 AM when temperatures are low and wind velocity is
reduced.
Follow the standard machine setup instructions, initial roller and
drag pan adjustments and roller rotation. It is important that
the burlap drag be soaked with water and continuously sprayed
during the pour. The deck surface should also be wet down
before the pour and not have a chance to dry out. Ahead of the
machine, spread and broom the material onto the deck, removing
most of the large aggregate. Brush the slurry onto the curbs or
adjoining slabs a minimum of 3 inches to insure a strong bond.
Do not place material over 5 feet in front of the machine.
SECTION 2
OPERATIONS
050362 Page 48
2.7 - Paving Operations, continued