A WIRTGEN GROUP COMPANY

Intelligent compaction OSCILLATION

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Oscillation technology delivers high-quality, cost-effective compaction in asphalt construction and earth work.

Oscillation – over 30 years’ experience

Compaction

Vibration

With vibration, a rotating unbalance forces the drum to undergo a rapid circular motion. This results in the bulk of the compaction energy being directed vertically into the soil, achieving deep penetration. The drum lifts off the ground after each impact. This means that around 50% of the time, the drum is not in contact with the ground.

Oscillation for asphalt construction and earth work

The HAMM programme contains oscillation drums for tandem rollers and compactors. This means that the intelligent compaction technology can be employed in both asphalt construction and earth work. All oscillation drums are manufactured in the HAMM drum factory using highly wear-resistant steels.

More than 30 years ago, HAMM developed oscillation and thereby revolutionised compaction technology. Today, HAMM offers more than 30 machine types with oscillation drum in all weight classes. Road construction companies all over the world love using this intelligent technology for asphalt construction and earth work. This way, HAMM is responding to the growing demands on high-quality compaction for the most diverse surfaces and building materials.

Asphalt

Asphalt compaction is mainly carried out using tandem rollers. On the models with oscillation, the oscillation drum is normally fitted at the rear. Its exciter system can simply be activated or deactivated by pressing a button.

Earth work

For earth work, HAMM has developed the VIO drum. It enables oscillation to be employed in compactors as well. Its unbalance system combines two compaction methods in a single drum, enabling compaction either with vibration or with oscillation. This solution is ideal for earth work, because the VIO drum is able to compact in depth with vibration and in the upper layer with oscillation. Switching between vibration and oscillation is carried out from the operator’s platform and can even be done with the roller in motion.

Oscillation

With oscillation, two unbalance shafts rotate synchronously. The unbalances are offset by 180°. This causes the drum to carry out a rapidly alternating forward-backward rotary movement, with the result that the compaction energy is directed into the soil tangentially to the front and rear in the form of shear forces. In contrast to a vibrating drum, it acts dynamically on the soil all the time. Because the drum is always in contact with the ground, there is also a constant static load due to the weight of the machine.

A brief explanation of vibration and oscillation

The compaction effect of rollers is always due to the weight that acts as a static load on the soil as they travel over it. If the drums are caused to vibrate at the same time, the compaction effect increases significantly. This is described as dynamic compaction.

Two successful principles are employed: vibration and oscillation. They differ in respect of the exciter system used and the resulting direction of force application.

Tandem rollers

Series HD CompactLineSeries HDSeries HD+Series DV+

Compactors

Series H CompactLineSeries HSeries 3000

Machine series with oscillation:

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Compaction with oscillation brings about an increase in quality – and is highly cost-effective, too.

• High compaction power • Fewer passes required• No over-compaction or grain crushing• High quality thanks to homogenous, smooth carriageways• Tight joints without damage to cold asphalt• Dynamic compaction even in vibration-sensitive areas• Efficient compaction at low asphalt or ambient temperatures enables compaction even within very tight working time windows

• Self-regulating system, requires no adjustments• Environment-friendly thanks to low noise level and reduced vibrations• Reduced vibrations make the machine components last longer and are less tiring for the driver

Benefits of oscillation Wide application spectrum• Compaction on major projects (motorways, racetracks, airfields, etc.) • Compaction on bridges, on ramps and in multi-storey car parks• Compaction in inner-city areas, in close proximity to historical or vibration-sensitive buildings

• Compaction of thin layers (surface courses or DSH-V thin overlays)• Compaction of difficult-to-compact asphalt types• Compaction of joints• Compaction above gas and water pipes• Compaction near railway installations• Compaction under difficult ambient conditions (cold, wind) or at low asphalt temperatures

Applications

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6100%

95%

90%

85%

Kontinuierlicher Bodenkontakt Keine Überverdichtung und keine Kornzertrümmerung

Perfekte Verdichtung von Nahtstellen

Die Naht zwischen zwei Fahrstreifen, z. B. bei der einseitigen Erneuerung einer Fahrspur, wird durch Einsatz der Oszillation, ohne Beschädigung der bereits bestehenden Fahrbahn, optimal verdichtet. Auch eine Verdichtung der Quernaht (Anschlüsse) ist ohne Weiteres möglich.

Ein weiteres Plus der Oszillation ist die perfekte Ebenheit.

Da keine vertikalen Schläge auf den Untergrund einwirken, entstehen keine Wellen oder Unebenheiten. Mittels Oszillation asphaltierte Fahrbahnen sind deshalb perfekt eben.

Ein weiterer Pluspunkt: Im Vergleich zur Vibration werden nur etwa 15 % der Erschütterungen in die Umgebung eingeleitet. Damit ist die effi ziente, dynamische Oszillationsverdichtung auch in der Nähe von schwingungsempfindlichen Gebäuden oder Anlagen und auf Brücken problemlos möglich.

Bei der Vibrationsverdichtung riskiert man bei zu niedrigen Asphalttemperaturen oder bei Überverdichtung eine Zerstörung des Materialgefüges oder Kornzertrümmerungen. Nicht so bei der Oszillation. Mit jeder weiteren Überfahrt steigt die Verdichtung – ganz ohne unerwünschte Nebenwirkungen.

Das Prinzip der Oszillation nutzt die physikalischen Gesetze intelligent aus. Abhängig von der Verdichtung des Materials ändert sich die Amplitude der oszillierenden Bewegung der Bandage von selbst:Je höher die Verdichtung des Asphaltes, desto geringer wird die Oszillationsamplitude. Ohne Voreinstellungen und ohne eine fehlerbehaftete Sensorik zur Steifigkeitsmessung passt sich das System dem Verdichtungszustand und Umgebungsbedingungen selbständig an.

Selbstregelnde Amplitude Mit der Oszillation erreicht man eine schnellere Verdichtungszunahme. Der Grund: Sowohl bei der Vorwärts- als auch bei der Rückwärts-bewegung der Bandage wird ihre dynamische Verdichtungskraft in das Material eingeleitet und das für die Verdichtung zur Verfügung stehende Zeitfenster optimal genutzt.

Oszillation ist die ideale Technologie zur Verdichtung dünner Schichten, schwer verdichtbarer Materialien oder in der Nähe von schwingungsempfi ndlichen Gebäuden oder Anlagen und auf Brücken. Überall dort ermöglicht sie hohe Verdichtungsleistung und effi ziente dynamische Verdichtung.

Beim Asphalteinbau auf Brücken und beim Einbau dünner Schichten kühlt der Asphalt schneller ab. Für die Oszillation kein Problem, da die Walzen auch noch bei niedrigeren Asphalttemperaturen effi zient verdichten.

Mit Oszillationswalzen lassen sich auch moderne, schwer zu ver-arbeitende Baustoffe wie z. B. Splitt-Mastix-Asphalt ausgezeichnet verdichten.

Verdichtungsarbeiten sind nur innerhalb eines bestimmten Temperatur-fensters möglich. Ist die Asphalttemperatur zu niedrig, kann die Vibra-tion zu Kornzertrümmerungen oder zur Zerstörung des Materialgefü-ges führen. Ab einer bestimmten Temperatur muss deshalb die Vibration ausgeschaltet werden. Mit der Oszillation hingegen kann auch bei nied-rigeren Asphalttemperaturen effi zient und gefahrlos verdichtet werden.

Mehr Zeit für die Verdichtung

Vorteile• Dauernde dynamische Verdichtung

• Geringe Erschütterungen des Umfeldes

• Dynamische Verdichtung auch in schwingungs-empfi ndlichen Bereichen

• Ideal für dynamische Verdichtung auf Brücken

• Ideal für dynamische Verdichtung über Gas- und Wasserleitungen, in der Nähe von Gleisanlagen usw.

Vorteile• Optimale und dynamische Verdichtung der Nähte

• Keine Zerstörung des bestehenden Belages

• Langlebige Verbindung

Vorteile• Hoher Verdichtungsgrad

• Keine Überverdichtung

• Intaktes Korngerüst

• Keine Kornzertrümmerung

• Optimal dosierte Verdichtungskraft

• Im Vergleich zur Vibration weniger Überfahrten nötig

• Schnellere Zunahme der Verdichtung

Vorteile• Immer die optimale Verdichtungsenergie

• Keine Voreinstellungen keine Fehleinstellungen

Vorteile

Vorteile• Auch für schwer verdichtbare Asphalte geeignet

• Ideal für dynamische Verdichtung von Dünnschichtbelägen

• Ideal für dynamische Verdichtung in schwingungs- empfi ndlichen Bereichen

Schnellere Verdichtungszunahme

Vorteile• Optimaler Fahrkomfort

• Keine Wellenbildung

Perfekte Ebenheit

• Größeres Zeitfenster dank Oszillation • Mehr Flexibilität • Ausgezeichnete Resultate auch bei niedrigen Asphalt- temperaturen oder widrigen Witterungsbedingungen

Vorteile

Löst auch schwierigste Fälle

140° C / 284° F 120° C / 248° F 100° C / 212° F 80° C / 176° F 60° C / 140° F

C°/F

OSZILLATION

VIBRATION

Größeres Zeitfenster dank Oszillation

WEICHER UNTERGRUND

HARTER UNTERGRUND

WEICHER UNTERGRUND

HARTER UNTERGRUND

HEISS KALT

VIBRATION

OSZILLATION

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2

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Rapid increase in compaction

Rollers with one oscillation and one vibrating drum achieve a much faster increase in compaction than rollers with two vibrating drums. This is because during both forward and backward movements, the drum directs its compaction force into the ground in the form of tangential shear forces. In doing so, the drum never lifts off the ground. Instead, the ground is compacted dynamically without interruption. In addition, a static load acts constantly on the asphalt or ground. This promotes a rapid increase in compaction. It speeds up the compaction process and ensures exceptionally smooth surfaces.

Minimal vibration in the surrounding area

Oscillation drums vibrate but neither lift off the ground nor cause vertical impacts. In contrast to vibrating drums, with oscillation drums only around 15% of the vibration is transmitted to the area surrounding the roller. This means that rollers with oscillation drum can also be used without problems for compaction near vibration-sensitive buildings or installations. This technology makes the components last longer, the rollers are markedly quieter and work is significantly less tiring for roller drivers.

Self-regulating system

Compaction with oscillation makes intelligent use of physics. The appropriate amplitude is adjusted automatically depending on the rigidity of the material to be compacted: the more rigid the asphalt or ground, the lower the amplitude. This adjustment occurs with every movement of the drum, that is to say at very shortintervals and minimal distances, without the need for an elaborate control system. Operator errors due to incorrect settings are thus excluded. Instead, this principle impresses with its efficient compaction even on changing soils.

High-quality joint compaction

Joints with existing asphalt surfaces, such as when refurbishing a single traffic lane, are best compacted using oscillation, that is to say without damage to the cold traffic lane. This allows connecting joints with existing asphalt to be compacted to a high standard of quality.

Neither over-compaction nor grain crushing

With vibration compaction, there is a risk of destroying the material structure or of grain crushing, from a certainlevel of rigidity. This is not the case with oscillation, however. Here, the aggregate particles are redistributednon-destructively. In this way, oscillation avoids detrimental grain crushing. Neither does any undesirabledrawing-up of water or bitumen occur with oscillation compaction. Instead, the rigidity, that is to say the compaction, increases with every pass.

More time for asphalt compaction

Asphalt can only be compacted during a specific, material-dependent temperature window. If the asphalt has cooled down too much, vibration may result in grain crushing or destruction of the granular structure or of the bonding of the layers. Oscillation, on the other hand, delivers a non-destructive increase in compaction even at lower temperatures. The compaction time window is thus markedly increased. For this reason, oscillation is particularly suited to the compaction of thin layers or on fast-cooling surfaces such as bridges.

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Using rollers with one oscillation and one vibrating drum, the level of compaction rises faster and achieves higher values than with rollers with two vibrating drums.

V+V

V+O

The oscillation principle: the more rigid the ground, the lower the amplitude.

UNCOMPACTED GROUND

ADVANTAGES

• Fewer passes• Constant dynamic compaction• Faster increase in compaction• High degree of compaction

ADVANTAGES

• Minimal vibration in the area around the machine• Dynamic compaction is also possible in vibration-sensitive areas (in towns, on bridges, above supply lines, near railway installations, etc.)

ADVANTAGES

• Optimum, dynamic compaction of the joint• No damage to the cold surface• Long-lasting joint

ADVANTAGES

• High longitudinal evenness• No rippling• High initial skid resistance• Greater driving comfort

ADVANTAGES

• Optimum compaction energy• Operator errors impossible

ADVANTAGES

• No over-compaction or grain crushing• Intact granular structure• No reloosening• No demixing due to drawing-up of bitumen or water

ADVANTAGES

• Larger time window• Greater flexibility• Efficient compaction even at low asphalt temperatures, with fast-cooling thin layers and in adverse weather

COMPACTED GROUND

Oscillation – the benefits at a glance

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Enlarged time frame with Oscillation

Perfect evenness and initial skid resistance

Surfaces compacted using oscillation exhibit excellent longitudinal evenness. It comes about because the drum remains in constant contact with the ground and no impacts occur that could produce irregularities in the ground or asphalt. Asphalt compaction with oscillation is also responsible for a good initial skid resistance, because the drum rubs off the bitumen from the top surface of the carriageway due to its oscillating movement – a plus factor for safety.

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Whatever the application in earthwork or asphalt construction: compaction with oscillation is fast and gentle.

Compaction on bridges

Rollers with oscillation drum are trumps for compaction on bridges. There, they are able to compact dynamically and efficiently, because there is no risk of the compaction work inducing dangerous vibrations at the bridge’s resonant frequency. Another benefit is the rapid increase in compaction. This is especially important on bridges because there the wind cools the asphalt layers quickly. In addition, tandem rollers with oscillation compact very efficiently even at lower asphalt temperatures.

Compaction of thin layers

Rollers with oscillation drum are the number one choice for compaction of thin asphalt layers because they quickly achieve the desired compaction. Moreover, tandem rollers with oscillation are able to compact thin layers per-fectly even at lower asphalt temperatures.

Top quality even on small asphalt repairs

Joints between new and existing asphalt rank among the critical points in carriageway refurbishment. Here, oscillation avoids damaging the existing or previously repaired cold carriageway. Even the smallest areas can thus be compacted durably and to a high standard of quality – including the transverse joints at the start or end of the area.

High-quality compaction in inner cities

On confined construction sites in city centres, dynamic compaction with oscillation is advisable. It is particularly safe because oscillation induces only minimal vibration in the adjacent area. For this reason, it avoids damage to the surrounding buildings as well as to pipework below the carriageway.

There are many good reasons for oscillation

Solution for difficult-to-compact asphalts

Rollers with oscillation technology achieve excellent compaction even of difficult-to-compact construction materials such as stone mastic asphalt or polymer-modified mixes. This is because, in contrast to vibration compaction, the effective direction of the vibrations during oscillation promotes the desired redistribution of the long-chain binding agents. The system has also proven its worth in the laying of compact asphalt pavements using the InLine Pave process.

More efficient compaction in landscape gardening

Oscillation compaction improves many land-scape gardening processes. Water-bound paths, for example, can be compacted much more efficiently with oscillation than with other technologies. Problems such as reloosening in the upper region or the drawing-up of water during ground compaction do not occur with this method of compaction.

Applications

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HAMM AGHammstrasse 1D-95643 TirschenreuthTel +49 9631/ 80-0Fax +49 9631/ 80-111www.hamm.eu

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