On this contract, asphalt base some 10m wide and 18cm thick had to be paved over a length of 10km. That alone was out of the ordinary. As an extra challenge, the base course was to be paved with an accuracy normally specified for wearing course. The demands were high as the project required a perfect base onto which to place binder and wearing courses "hot-on-hot" without any further grade and slope control.

To master this challenge, German contractor Bunte of Papenburg opted for its large VÖGELE paver, a SUPER 2100-2. The paver moved onto the site with a SB 250 Fixed-Width Screed in TP1 Version for high compaction, fitted with hydraulic bolt-on extensions. Based on this technology, paving in the specified width of more than 10 metres was no problem at all. Which left the question of accuracy. As earthworks and the water-bound base had been carried out using 3D control systems, meanwhile common practice on large-scale projects, it was a logical step to use the existing survey data for asphalt paving as well.

NAVITRONIC Plus® takes over control of the paver

The paver was equipped with NAVITRONIC Plus®, the 3D Machine Control System offered by VÖGELE. This system allows paving to the highest standards of accuracy without a need for time and cost-consuming tensioning of wires.

NAVITRONIC Plus® comes with an open interface, so that positioning systems of different makes can be connected. As for earthworks, equipment made by TopCon had been used, it suggested itself to also dock a TopCon mmGPS positioning unit to the paver’s NAVITRONIC Plus®.

The TopCon unit combines satellite-based and laser-based measurements. As purely satellite-based systems still cannot achieve more than an accuracy in the range of centimetres, the TopCon mmGPS unit uses an additional laser receiver to obtain extra information for the screed’s elevation. Based on this combination of satellite-based and laser-based measurements, the machine’s location can be calculated with the high millimetre accuracy required in road construction. Signals from both sources are processed by the positioning system and a comparison is made with the route’s specified design data. The results are transmitted from the TopCon unit‘s computer to VÖGELE’s NAVITRONIC Plus®.

Fully automatic control of the screed’s position and the paver’s direction of motion

At this point, NAVITRONIC Plus® takes over full control of the machine. In the event of deviations in terms of layer thickness or slope, signals are emitted to NIVELTRONIC Plus®, the System for Automated Grade and Slope Control, and corrections are initiated automatically. Minor deviations in terms of screed position are corrected by way of the screed’s hydraulically extending units. In the event of major deviations and in bends, NAVITRONIC Plus® intervenes in the paver’s steering, thus locating both tractor and screed in compliance with the specified course of the route. This fully automatic control of both the screed’s position and the paver’s direction of motion makes VÖGELE NAVITRONIC Plus® unique in the market.

To ensure a sufficient supply of the large SUPER 2100-2 with mix at all times, a VÖGELE MT 1000-1 Mobile Feeder was on the scene, too. This way, continuous paving was guaranteed throughout the project with laydown rates between 3,500 and 4,000 tonnes a day.

Thanks to all these factors, an asphalt base course perfect in terms of width, layer thickness and screed position could be paved economically within the specified period of time. An accurate base was created on which further courses can be paved without difficulty. The excellent result also impressed contractor Bunte, who decided to include VÖGELE NAVITRONIC Plus® in the company’s equipment pool, so that future contracts can also be handled cost-efficiently and with highest precision.

Press and product information:

JOSEPH VÖGELE AG

Press and Public Relations

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Germany

Tel.: +49 (0) 621 8105 202

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presse@voegele.info

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