Hot to Hot the Whole Night Long

Transcription

1 Spray pavers rehabilitate a section of the A 99 motorway near Munich, Germany. Hot to Hot the Whole Night Long

2 Spray pavers rehabilitate a section of the A 99 motorway near Munich, Germany. Hot to Hot the Whole Night Long Four SUPER with SprayJet Module paved a thin, noise-reducing asphalt overlay on spray seal, hot on hot, on the A 99 to the west of Allach Tunnel. For pavement rehabilitation, this stretch of the busy orbital motorway near Munich could only be closed to traffic at night no problem for the time-saving SprayJet technology. Seite 1/7 Job Site Details 1/2 Paving thin overlay on spray seal, hot on hot (DSH-V), for noise reduction on the A 99 motorway west of Allach Tunnel, Munich, Germany Length of job site: 800m Width of job site: 16 19m Paving Details Pave width: m Layer thickness: binder course 5.5cm wearing course 1.5cm Material Binder course: AC 16 D S Wearing course: DSH-V 5 Emulsion: C67BP5-DSH-V Rate of spread: 0.35kg/m2

3 The traffic volume on the A 99 orbital motorway near Munich is between 100,000 and 120,000 vehicles a day. Roadworks can only be carried out at night, as the resultant traffic obstructions would simply be too great during daytime hours. It would be even better if multiple construction jobs could be carried out simultaneously. When recently the Allach Tunnel on the A 99 also had to be modernized, the decision was made to take advantage of the nightly motorway closures to improve noise protection, too. To the west of the tunnel, the old wearing course was replaced with a new thin overlay paved on spray seal, hot on hot. Layers like these reduce the noise generated by traffic by as much as 4 db(a). The contract for the rehabilitation work was awarded to Max Streicher GmbH & Co. KGaA from Deggendorf. Seite 2/7 Job Site Details 2/2 Paving thin overlay on spray seal, hot on hot (DSH-V), for noise reduction on the A 99 motorway west of Allach Tunnel, Munich, Germany Enormous time pressure The section of road involved began about 30m inside the Allach Tunnel and extended some 600m in the direction of Salzburg and some 800m in the direction of Stuttgart. The time pressure was enormous, as everything had to be completed in just three nights. In the first night, two WIRTGEN milling machines removed the old pavement to a depth of 7cm. In the second night, the new 5.5cm binder course was placed. More than 30 light balloons illuminated the job site. Length of job site: 800m Width of job site: 16 19m Equipment 2 WIRTGEN W 2100 Milling Machines 4 SUPER with SprayJet Module as well as AB TV, AB TP1 and AB TP1 Extending Screeds

4 Four pavers worked in echelon hot to hot Once these preparations were completed, the new noisereducing wearing course could be paved in the final night. On this job site, four VÖGELE SUPER with SprayJet Module worked in echelon hot to hot. They applied the bitumen emulsion type C67BP5-DSH-V accurately and at precisely the selected rate of spread and, at the same time, placed 1.5cm wearing course of asphalt type DSH-V 5. By the way: both the asphalt and the emulsion meet the requirements of the new Supplementary Technical Contract Requirements and Guidelines for Structural Preservation of Traffic Areas Asphalt Pavements, ZTV BEAStB 09 ( Zusätzlichen Technischen Vertragsbedingungen und Richtlinien für die bauliche Erhaltung von Verkehrsflächen Asphaltbauweisen ). Three of the pavers were equipped with AB Extending Screeds and operated in varying widths between 2.55 and 5m. The fourth paver came with an AB Extending Screed working across a pave width of 3m. The result was a new, low-noise wearing course, between 16 and 19m wide. Saving time was decisive The SprayJet method as such is a fast procedure, but pavers working in echelon speeded it up even more. Our client decided in favour of VÖGELE SprayJet Technology primarily for reasons of time, confirmed Site Manager Tobias Feigl. The road had to be opened to traffic at five o clock every morning, sufficiently cooled, with road markings applied. This was only possible thanks to the well-proven VÖGELE technology, which completes two operations simultaneously: spreading bitumen emulsion and paving asphalt. Furthermore, the thin overlay cools faster than a layer of conventional thickness. Seite 3/7 Job Site Details 1/2 Paving thin overlay on spray seal, hot on hot (DSH-V), for noise reduction on the A 99 motorway west of Allach Tunnel, Munich, Germany Length of job site: 800m Width of job site: 16 19m Paving Details Pave width: m Layer thickness: binder course 5.5cm wearing course 1.5cm Material Binder course: AC 16 D S Wearing course: DSH-V 5 Emulsion: C67BP5-DSH-V Rate of spread: 0.35kg/m2

5 Road durability for many years The hot to hot operation across varying pave widths presented no problems at all for the paving teams and their machines. And grade and slope control also proceeded smoothly as usual. For perfect grade and slope control, the outermost pavers were equipped with multi-cell sonic sensors tracking the edges of the existing road, left and right. The two pavers following behind also used sonic sensors for referencing from the freshly paved strips. The result was an absolutely even pavement meeting all demands in terms of noise reduction and able to withstand the high traffic load for many years. Seite 4/7 Job Site Details 2/2 Paving thin overlay on spray seal, hot on hot (DSH-V), for noise reduction on the A 99 motorway west of Allach Tunnel, Munich, Germany Also suited for difficult job sites Top-class and absolutely reliable technology was all the more important in view of the tough conditions on the job site, explained Feigl: Inside the tunnel, three pavers worked in echelon, with the fourth joining them after the tunnel. What s more, a slight crown had to be paved at the bifurcation of the two carriageways. Thanks to the proven ErgoPlus operating system, however, this task was child s play for the paving teams and the sophisticated VÖGELE technology soon dispelled any doubts: The initial nervousness of the teams quickly disappeared. Everyone involved in the job was relaxed and in a good mood, despite working at night. Length of job site: 800m Width of job site: 16 19m Equipment 2 WIRTGEN W 2100 Milling Machines 4 SUPER with SprayJet Module as well as AB TV, AB TP1 and AB TP1 Extending Screeds

6 The Spray Technology The VÖGELE SUPER with SprayJet Module is equipped with five spray bars. The front spray bar has six spray nozzles and is located between the machine s crawler tracks right behind the push-rollers. Two articulated spray bars are installed on each side of the machine, with 7 nozzles per side. A short spray bar with two nozzles is located directly behind each crawler track. This arrangement of the spray bars allows full coverage of the existing surface with emulsion, with no bald spots, even if the pave width varies. Much like the functionality of an ink jet printer, the nozzles of the VÖGELE spray paver do not spray continuously but in pulsed operation. The frequency of the spray pulses is adjusted automatically as a function of the selected rate of spread, pave speed and pave width. As a result, complete coverage of the existing surface with a uniform film of emulsion is achieved, without any overlaps. 01 // 01 // The double-slotted high-quality spray nozzles guarantee perfect spraying. Seite 5/7

7 Seite 6/7 Both Mix and Emulsion Complying with German Guideline ZTV BEA-StB 09 In 2009, a new issue of the German Supplementary Technical Contract Requirements and Guidelines for Structural Preservation of Traffic Areas Asphalt Pavements, ZTV BEAStB 09 was published. For the first time, thin asphalt overlays paved hot on hot on spray seal (DSH-V) have been included in these guidelines as a construction method. The guidelines ZTV BEA-StB 09 were elaborated by the Road and Traffic Research Association (Forschungsgesellschaft für Straßen- und Verkehrswesen) and approved by the Federal Ministry for Traffic, Construction and Urban Development as well as the road building authorities of the German Länder. As a result, this method now belongs to the highest class of Generally approved rules of construction. The bitumen emulsion type C67BP5DSH-V, too, complies with the requirements of the guidelines ZTV BEA-StB // 02 // One of the four SUPER with SprayJet Module. The tank was filled with bitumen emulsion type C67BP5-DSH-V complying with the requirements of the new German guideline ZTV BEA-StB 09.

8 Seite 7/7 How Thin Asphalt Absorbs Noise A // The rolling noise caused by vehicle tyres is responsible for the majority of traffic noise. This noise is generated by air escaping from the cavities in the tyre s profile and small irregularities deforming the tyre. B // The surface of a low-noise wearing course is structured much like a plateau with ravines. This results in less deformation of a vehicle s tyres, causing less noise to be generated. C // The noise is dissipated by cavities in the layer. The maximum grain size is 5 to 8mm (approx.). This prevents the formation of large cavities that are easily clogged with dirt. D // The seal protects the lower layers and ensures long-lasting road durability. Supplementary, complex drainage systems are unnecessary.