Compaction of the asphalt pavement should yield a uniform surface with the greatest possible skid resistance and ensure that the individual asphalt courses are firmly and durably interlinked to produce high stability and wear resistance, as well as enduring evenness. Rollers or compactors by Hamm reduce the number of voids. This makes the asphalt more resistant to stress and extends its durability.
What type of mix will be compacted, and what are the thicknesses of the individual layers? Where’s the job location? On a motorway, in a residential area, on a bridge? The answers to these questions will determine the type of roller to be used for compaction. What will be the paving width and paving speed? That will determine the number of rollers to be used.
Dynamic compaction on an elevated road or bridge is possible with HAMM oscillation technology. This system allows even thin layers to be compacted without stressing the structures.
Getting the rollers ready
Rollers are heavy road construction machines used for compacting hot and therefore flexible asphalt pavements. To prevent them from causing damage to the new asphalt surface, they must not come to a halt during the compacting operation. For precisely that reason, machine maintenance is of particular importance. In addition to that, checks need to be carried out prior to commencing work to make sure that the drum is clean, that fuel and engine oil are available in sufficient quantities, and that the water tank has sufficient water for the drum spray system.
Because of their free-view concept with panorama cabin, the tandem rollers of the DV series offer an exceptionally good view of the drum and the working environment.
The manoeuvrable small tandem rollers with operating weights ranging from 1.4 to 4.2 tons impress with their high power of compaction.
Their kneading effect enables the pneumatic tyred rollers to produce an excellent pore seal and superior surface finish.
Combination rollers from HAMM – like the roller of the HD series shown here – offer an ideal mix of static and dynamic compaction.
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The effect of temperature on the compaction result
Basically, compaction becomes more effective with increasing temperature of the paved mix. The most advantageous temperature range depends on the composition of the mix, the thickness of the pavement and the type of binder used.
“Dynamic compaction with HAMM oscillation rollers is ideal to prevent damage to the underlying cold layer.”
The roller operator starts compaction at the tie-in points and follows the edge of the road from there. The pavement is pressed home in a further pass. Dynamic compaction is mainly used for the main compaction process. The drums vibrate horizontally (oscillate) or vertically (vibrate), thus significantly increasing the effect of compaction. The operation is completed by a final roller pass that will “iron out” any remaining irregularities in the asphalt pavement or surface to produce a perfect surface finish.
