Practical answers to the questions our application engineers hear most often from road builders and earthwork contractors.
Vibration produces vertical impacts that densify the material beneath the drum. Oscillation produces horizontal shear forces that achieve compaction without transmitting vibrations downward — ideal for bridge decks, near buildings, and thin asphalt overlays where vibration could damage the substrate. Hamm HD-series rollers offer both modes selectable from the cab.
For a standard 60mm wearing course at 140–160 C mat temperature, a 10–12 tonne tandem roller typically achieves 96% density in 5–7 passes (2–3 static + 3–4 vibratory). The exact number depends on mix design, ambient temperature, and wind speed. Our application engineers provide a recommended rolling pattern specific to your conditions.
Padfoot drums are designed for cohesive soils — clays, silts, and clayey gravels with plasticity index above 8. The pad feet knead and shear the material for deeper compaction penetration compared to smooth drums. For granular materials (sand, gravel, crushed rock with PI below 8), smooth drums are more effective.
For conventional hot-mix asphalt, initial compaction should begin above 130 C and finish above 80 C. Warm-mix asphalt (WMA) can be compacted 20–30 C lower. Our intelligent temperature monitoring systems display real-time mat temperature on the roller operator screen, helping crews optimize the compaction window.
Yes. Our HCQ (Hamm Compaction Quality) system provides real-time pass mapping and stiffness measurement (EVIB) displayed on the cab-mounted touchscreen. Data exports to standard formats for contractor quality reports and client acceptance documentation. Available as standard on HD-80 and HD-120 models, optional on lighter machines.