MANUAL 4 - Construction Industry Development Board

MANUAL 4 – BITUMINOUS PAVEMENT SEALS
2.8.2 Overlap
The ideal height h of the spray lance must be in such a position that it obtains an overlap of
approximately half the width of one jet. It is better to have h slightly higher than lower.
Try to keep h a constant height while spraying, to obtain a uniform overlap and therefore a
uniform application.
Figure 4.3: Spraying height and sequence of spraying
Once the correct height h for spraying above the road surface has been determined, it can
be maintained by tying a piece of wire of the correct length to the lance as illustrated in
Figure 4.4.
2.9 Application of binder
2.9.1 Checks
Figure 4.4: Maintaining correct height for spraying
Before spraying of the binder commences, the following checks must be done:
• Ensure that there is sufficient emulsion, aggregate, diesel fuel and paraffin on site to
complete the work. To do this, the area to be surfaced and the rate of application of
the binder and aggregate, must be established.
IMPLEMENTING EMPLOYMENT INTENSIVE ROAD WORKS 19
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