Lesson 3/Learning Event 1
Learning Event 1
PLACING AND SPREADING OF HOT MIX MATERIALS
PAVING OPERATION PLANNING
Before spreading with a paver, design a plan for placing the paving strips. Both binder and
surface courses are to be laid so that the longitudinal joints are offset by at least one foot.
Overlapping of successive courses (Figure 8) helps prevent a crack opening along a longitudinal
joint.
FIGURE 8. OVERLAPPING OF SUCCESSIVE COURSES
You will need to make a general paving lane plan before laying any of the binder course in order
to avoid problems with longitudinal joints in the surface course.
SPREADING HOT MIX MATERIALS
Pavements for Air Force bomber and fighter aircraft and modem high speed road traffic must be
extremely smooth. Therefore, long wheelbase motor graders often are used for spreading both
hot and cold asphalt plant mixes in base and leveling (binder) courses. The principal advantage
of using the long wheelbase to lay the leveling course is the elimination of excessive humps,
sags, and irregularities in the subgrade, base, or old pavement on which the mix is to be placed.
Another benefit of laying a leveling course with a motor grader is a rough textured surface on
which to place the surface course.
Do not attempt to spread with the motor grader unless the grader operator is highly skilled and
experienced. An unskilled operator may do more damage than good.
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