. Keep the area clear of open flame or sparks to
reduce fire hazard when you are spraying material with
. Do not stand in a location in which the accidental
opening of the spray bar valves will cause contact with
the bitumen spray. This is important, because you could
receive serious burns if you do not.
l The fill line cap or connection must be securely
attached before operating the intake valve lever to
eliminate momentary discharge.
. The TUC bar must be off and remain off when
the bar is rotated upward.
. When moisture is present in the tank, do not load
the tank with material having a temperature over 200°F.
To prevent foaming when filling a unit in which moisture
may be present in the spray bar or the circulating system,
you should allow a small portion of hot material to circulate
in the spray bar before filling the tank.
. When you are heating material, if at all possible,
position the unit broadside to the wind.
. The use of gasoline instead of regular kerosene
or fuel oil on low-pressure burners will result in an
extreme fire hazard.
. Do not operate burners unattended (unless a
safety control is provided) or while the vehicle is in
transit or in a confined area.
l When heating, you must allow sufficient space in
the tank for expansion of the material.
. To prevent a possible explosion, you must cover
flues with at least 6 inches of bitumen before heating the
material, This layer of bitumen reduces the vapors
produced, thereby, reducing the chance of an explosion.
l For personal safety, use a torch (not a match or
lighter) to ignite the burner.
. Ignite the inside burner first. Do not reach across
a lighted burner to ignite the inside burner.
. When burners go out, allow time for ventilation
. Do not heat material beyond the manufacturers
. When you are hand spraying, hold the sprayer in
the proper position and be aware of other personnel in
. Emulsified asphalts should never be left in the
distributor truck for any great length of time.
Emulsified asphalts will separate and set in much less
time than will cutbacks.
. Avoid inhaling the vapors or mist from sprayed
asphalt, or prolonged skin contact with asphalt products.
Asphalt materials contain compounds known or
suspected to causes cancer. Hot asphalt is a bum hazard
and can cause serious eye damage.
ASPHALT HAUL TRUCKS
Various types of trucks are used to deliver hot mix
to the paver. The most common type is the 5-ton
end-dump truck but other trucks have been used and
can be used to deliver mix.
Trucks must have metal beds, and the beds must be
clean, smooth, and free of holes. All trucks must meet
minimum safety criteria. Each truck must be clearly
numbered for easy identification and must be equipped
with a tarpaulin.
Before being loaded, the truck bed must be cleaned
of foreign material and hardened asphalt and then lightly
coated with a release agent (lubricant) that assists in
preventing fresh hot-mix asphalt from sticking to the
surfaces of the bed. After the bed is coated, any excess
release agent must be drained from the bed. Before
loading, the truck must also be weighed to establish its
unloaded weight. This weight is later subtracted from
the loaded weight of the truck to determine the weight
of the hot mix that the truck is hauling.
The number of trucks required on the project is
determined by many factors: the mix production rate at
the plant, the length of the haul, the type of traffic en-
countered, and the expected time needed for unloading.
Types of Trucks
Each type of truck used for hot-mix delivery must
have certain physical features that are required to haul
properly and to discharge the mix properly into the
paver. Below are listed a few guidelines for the two
most common types of trucks.
END-DUMP TRUCKS. An end-dump truck
must first be inspected to be certain the rear of the bed
overhangs the rear wheels enough to discharge mix into
the paver hopper. If it does not, an apron with side plates
must be added to increase the overhang and prevent
spillage of the mix in front of the paver.
The bed must also be of a size that will fit into the
hopper without pressing down on the paver. The