JOB REPORT

No trade barriers for Palatschinken and pasta.

Asphalt compaction on Austria’s A2 motorway

The A2 is Austria’s longest and oldest motorway, leading from Vienna to the Italian border. The transit route needs to not only cope with 145,000 vehicles per day but to also withstand a high percentage of heavy traffic. The tremendous stresses eventually called for rehabilitation of the slow lane and hard shoulder over a section of 10 km length.

To achieve maximum efficiency and power of compaction, the asphalt pavement was to be compacted using Hamm rollers with oscillation and vibration. A total number of ten tandem rollers of the HD series with oscillation and vibration drums were used for compaction of the four asphalt layers. Following the removal of the old concrete pavement, which had been overlaid with asphalt, the tandem rollers initially compacted a levelling course that would ensure the safe drainage of water ingressing from the upper pavement layers.

Next came two base layers consisting of one 10 cm bituminous base layer and a second 10 cm, high-strength bituminous base layer. The final layer consisted of a 3 cm surface course of chipped stone mastic asphalt.

The four asphalt layers were compacted in two passes applying vibration and three passes applying oscillation. This rolling pattern quickly resulted in a high density of well over 100%. The client’s technical director was impressed with the advantages offered by the rollers from Hamm, “Just a few roller passes were needed to achieve excellent density and a high degree of evenness, and the pavement had excellent grip right from the start.”