Solutions for compacting warm-mix asphalts

23 January, 2025

Warm-mix asphalt compaction with a Hamm HX-series tandem roller

First published in the January 2025 issue of Quarry Management

Specialist Hamm technologies for high process reliability

Warm-mix asphalts are becoming increasingly important in road construction, and offer great potential for saving energy and cutting CO2 emissions. Plus, the associated lower levels of vapour and aerosol are also beneficial in terms of occupational health and safety. Compacting with these types of asphalt means a shorter time frame in which to achieve optimum results. This is where Hamm come in with various solutions to support the operator in their work process and to ensure high-quality surfaces.

The most effective method for compacting warm-mix asphalts is the long-established oscillation method. Since the oscillation drum is in constant contact with the substrate, the compaction rate can be faster. As well as being gentler on materials than the vibration method, oscillation ensures that surface damage is avoided when compacting at lower asphalt temperatures. In the compaction of joints, oscillation again plays to its strengths by preventing damage to the already cooled asphalt. Overall, using oscillation increases the time frame available for compaction before the material’s rigidity dramatically increases and the asphalt becomes difficult to work with.

Another solution for achieving a high level of process reliability is the Smart Compact compaction assistant, which controls the compaction energy and compaction modes in both drums on tandem rollers in the HX series by constantly monitoring the cooling behaviour of the asphalt and the current rigidity values. Smart Compact then determines on the operator’s behalf whether compaction should be static or use vibration or oscillation and selects the necessary compaction energy. This effectively prevents over-compaction, minimizes surface damage, and reduces the number of double passes. In this way, Smart Compact increases the efficiency of compaction and makes optimum use of the time available, which represents major added value in connection with warm-mix asphalts.

With the help of the Smart Doc Android app, the driver can now keep a constant eye on all compaction parameters, including important asphalt temperature data

Establishing a high degree of transparency around the compaction process also promotes the most effective possible use of the time available. This is where Smart Doc comes in. Another digital solution from Hamm, it informs operators about compaction values, the number of double passes, asphalt temperatures, and other compaction parameters at any time. With this constant and full transparency around compaction processes, operators can compact warm-mix asphalts more easily. The number of unnecessary double passes is also reduced, meaning the operator can make optimum use of the time frame available for compaction.

Even the HD 10e and HD 12e battery-powered electric tandem rollers can be used to compact warm-mix asphalts. Hamm say they are the only manufacturer in this segment to offer sales variants with an oscillation drum and a set of tyres. These can also be fitted with thermal aprons, which stop the tyres from cooling down. Moreover, these models bring with them all the benefits of oscillation.