Then roll the joint when rolling the second mat.
(b) When laying one mat some distance ahead, so that the material sets up or traffic causes
compaction the second mat should be thick enough to allow for compaction. The full width of this mat should be
rolled.
(c) When matching a previously rolled mat, allow for the compaction of the roller. The screed should
never ride on the first mat. (Refer to Figure 6)
(d) Roll the mat joint as soon as possible behind the paver.
(e) When it is important to maintain a straight crown in the middle of a wide road, it is usually desirable
to lay the middle mat first.
(f) When paving narrow roads that do not give sufficient clearance on the shoulder for the screed on
the cut-off side, the operator can lay the first mat the narrow width. When a crown is to be maintained in the
center of the road, match with cut-off shoe riding the previously laid mat.
(g) When matching one mat with another, a 6" or 1' extension should be used on the side of the
matching joint, if possible. This will allow the usual wear experienced when overlapping to take place on the
short extension rather than on one end of the screed plate.
(2) Transverse Joints-When making a transverse joint, the operator should take into consideration whether
or not the material will set up before the paver is returned to make this joint.
(a) If the joint will be made before the asphalt sets up, the roller should not roll the last two yards of the
mat.
(b) When making the joint, raise the screed and back up, so the entire screed will rest on the mat.
(c) Then lower the screed, fill up the screw conveyor with material and start normal operation.
(d) The screed should be adjusted to the same position as when this mat was ended. Screed can be
adjusted while resting on mat.
(e) When a transverse joint is being made to a compacted mat, the same procedure is followed, and
the operator should allow for the roller compaction of the new mat.
Ending A Mat
When ending a mat of asphaltic paving where a transverse joint will be made, a vertical edge should be left
to accomplish a good bond in the transverse joint.
Ending A Mat
Figure 7
There are several methods that are used to end a mat to insure a good transverse joint.
(1) One of the simplest methods used is to use a piece of paper about 3' wide and a little longer than the width
of the mat.
(a) The operator should run the slat conveyors and spreader screws until all the material is used up.
(b) Stop the slat conveyors and spreader screws. Operate screed lift enough to snug lift cables and partly
support the screed, then move the paver forward until the screed has cleared the mat.
(c) Raise the screed and move the paver forward to allow working room.
(d) Rake the material evenly across the width of the mat.
(e) Lay paper across the width of mat, Figure 7
(f) Rake the material evenly onto the paper the same thickness as the mat.
CONDITIONS ENCOUNTERED IN PAVING
The following information is designed to aid the operator when faced by various conditions that are
encountered during paving operations. While it would be impossible to cover all conditions, the following are
the most common in everyday operation.
General
Inspect the road ahead of the paver; watch for grade changes, and adjust screed thickness controls gradually
to compensate for these changes in grade.
(1) Mat thickness cannot be held to a fine measurement. Material will be thinner over high spots and thicker
over low spots. Always maintain a level surface.
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