Page 12 - Structural Highway Design_Neat

• pattern that each roller uses.
Compaction Sequence

Figure 6-52. Breakdown and Intermediate Rollers.

5.6. Roller Speed

Rollers are slow; the fastest, operating speeds may reach about 11 km/h (7 mph).
In order to provide complete and uniform mat compaction, rollers should be
operated at a slow, constant speed. Operating at high speeds will reduce
compactive effort while varying roller speed can cause non-uniform compaction.
The following table shows typical roller speeds.

Type of Roller Breakdown Intermediate Finish
Static Steel Wheel 4.8 – 8.0 km/h
Pneumatic 3.2 – 5.6 km/h 4.0 – 6.5 km/h (3.0 – 5.0 mph)
Vibratory Steel Wheel (2.5 – 4.0 mph) 6.4 – 11.2 km/h
(2.0 – 3.5 (4.0 – 7.0 mph)
mph)
not used
3.2 – 5.6 km/h 4.0 – 6.5 km/h
(2.5 – 4.0 mph)
(2.0 – 3.5
mph)

3.2 – 4.8 km/h 4.0 – 5.6 km/h
(2.5 – 3.5 mph)
(2.0 – 3.0
mph)

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