KNOW-HOW

Paving roads at full pressure.

High compaction with tamper, vibrator and pressure bars

In asphalt paving, compaction is of vital importance. That applies not only to compaction by rollers but includes the road paver, as the asphalt material is pre-compacted by the paver’s integrated screed. Tamper and vibrator are normally used for standard compaction, whereas the high compaction screeds from Vögele use three compacting systems: one each tamper and vibrator, as well as one or two pressure bars which guarantee maximum density.

The tamper for pre-compaction

The tamper inside the screed ensures optimum pre-compaction of the material. Driven by an eccentric shaft, it tamps the asphalt mix beneath the screed body. The intensity of compaction is determined by the tamper’s speed and stroke. In Vögele screeds, both can be set with pin-point precision and adjusted to perfectly match the material flow, type of mix and layer thickness.

The eccentric vibrator for grain size distribution

Following pre-compaction by the tamper, the screed plate is made to vibrate along with the screed frame by means of eccentric vibrators, which results in an optimum distribution of the different grain sizes in the mix. The speed of the eccentric vibrators should be adjusted to the layer thickness and thus the grain size. It needs to be higher for thick pavements like, for instance, base layers than for thin layers with small grain sizes.

Pressure bars produce the highest pre-compacted density in the world

The third system that is part of Vögele’s high compaction technology consists of one or two pressure bars which achieve very high density values. In the Super pavers from Vögele, the tremendous pressure needed for the pressure bars is generated by pulsed-flow hydraulics – an innovative development by Joseph Vögele AG. The pressure bars are the actual core of Vögele’s high compaction technology. The unique technology enables the paving screed to achieve the highest densities a road paver can achieve.

Paving true to line, level and evenness

The pressure bar presses the material down during the paving operation until the mix cannot be compressed – and thus compacted – any further. In the process, an equilibrium of forces is generated between the pressure bar and the compacted material, which not only permits maximum accuracy to be achieved in terms of line, level and evenness, but also enables paving with exceptional economic efficiency.