Asphalt compaction

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.

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.

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.

The different roller passes

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.