Neckarau overpass, a railroad bridge adjacent to VÖGELE’s main plant, is one of Mannheim’s main traffic arteries. Built in 1936, the overpass represents an important link leading the traffic flow from the south of the Rhein-Neckar region into the city of Mannheim. Some 60,000 vehicles pass over the bridge each day, together with several tramlines running every five minutes. Corrosion had caused heavy damage to the steel girder bridge, well advanced in years, so that a decision was taken for new construction. During the last months, there was a speed limit of 30km/h for vehicles passing the bridge and those exceeding a maximum weight of 16t were banned.

Provisional bridge keeps the traffic artery alive

As to the construction project, an important objective was not having to close Neckarau overpass to traffic during the period scheduled for building the new bridge. Therefore, in mid-2007, construction work for a provisional bridge began next to old one. After completion of the structure, new carriageways and the track system for the tramway had to be installed. Construction firm Achatz-Bau was awarded the contract for building the access areas to the bridge, carrying out asphalt surfacing and installing the tramway tracks. For asphalt paving, the company used a small VÖGELE SUPER 800 combined with an AB 200 Extending Screed in TV version and placed roughly 80 tonnes of asphaltic concrete (0/11 S) for the wearing course. The provisional bridge will handle traffic until the end of 2009.

Asphalt paving between tramway tracks

“Paving the asphalt flush with the tram tracks wasn't the biggest challenge”, says site manager Uwe Hennigfeld, relaying his impressions of using the paver. “Absolutely great was the system for pave width reduction. This system enabled us to fix the pave width at 0.9m and then lay the asphalt very accurately between the tracks. We’d never experienced that with other pavers before.“ VÖGELE had put a lot of thought into the design of their small pavers so that even narrow pave widths can be realized very conveniently. One such feature is a special system for pave width reduction. Once mounted, the system allows infinite variation of the pave width between 1m and 0.5m. This is conveniently handled from the screed console without any need for further conversion.

The SUPER 800 used on this job site was also equipped with NIVELTRONIC® SC, a version of VÖGELE’s NIVELTRONIC® technology especially offered for the small pavers. NIVELTRONIC® SC is very easy to operate, so that perfect grade and slope control on the bridge was child’s play for the paving team.

Good pre-compaction achieved

On the provisional bridge, the pave width beyond the tramway tracks was a maximum of 2.1m. Good pre-compaction had already been achieved by the AB 200 Extending Screed in TV version so that no more than a few passes with a small HAMM DV 13 roller were required to produce the final density.

System for Pave Width Reduction Allows Minimum Width of 0.5m

When developing their small SUPER 800, VÖGELE put a lot of thought into a design providing economical efficiency when using the paver on minor job sites. Narrow pave widths are frequently required for these applications, for instance when it comes to backfilling trenches as shown here. In order to allow even narrow widths to be realized conveniently, VÖGELE offer a system for pave width reduction. Conceived especially for the small pavers, it reduces the machine's pave width from 1m to a minimum of 0.5m.

Optimal profile accuracy even in tight corners

With the system for pave width reduction installed, the material flow is already decreased to the desired width in the auger tunnel in front of the screed. This is an advantage over conventional cut-off shoes fitted beneath the augers and the screed. Due to the system, the mix arrives exactly where it is needed, thus creating a perfect pavement surface.

Automated grade and slope control can still be used

Another crucial advantage: with the system offered by VÖGELE, the screed floats on the mix just as it does when paving in a non-reduced width. This allows the layer thickness to be adjusted via the screed tow point rams and even to be controlled with NIVELTRONIC® SC, the System for Automated Grade and Slope Control. The floating screed not only provides for precise paving results, but also achieves excellent pre-compaction.

Job Site Details

Paving wearing course on a provisional bridge in Mannheim, Germany

Paving Details

Pave width: between 0.9m and 2.1m

Layer thickness: 4cm

Paving Material

Asphaltic concrete (0/11 S)

Equipment

SUPER 800 with AB 200 Extending Screed in TV Version