Perfect Evenness and Maximum Compaction
VÖGELE rehabilitates “Vehicle Dynamic Assessment Pad” of Continental, USA.
A SUPER 2100-2 replaced the asphalt pavement of the “Vehicle Dynamic Assessment Pad” (VDA Pad) at the Continental Proving Grounds in Uvalde, Texas (USA). To ensure totally reliable results in tyre tests, the evenness of the pavement had to meet extremely exacting standards. Selecting a high compaction screed for the paving work helped produce a top-quality pavement.
Selected drivers can really put their foot down in Uvalde, Texas. A little over 110km from the Mexican border, this is the home of the Uvalde Proving Grounds of tyre manufacturer Continental Tire the Americas, LLC. Continental’s 2,023 hectare site includes 11 different courses for testing its tyres in the toughest conditions: a high-speed oval, various asphalt, cement, gravel and mud courses, rocky terrain and numerous special test courses. The climate is ideal for testing purposes, with mild to warm temperatures prevailing year-round in the region.
Continental prefers to produce its own bad weather – to be precise, the tyre manufacturer uses, among other things, its “Vehicle Dynamic Assessment Pad” measuring 60.000m² whose asphalt pavement has now been rehabilitated by a SUPER 2100-2.
The pad has a 1% slope and can be flooded with water to a depth between 1.3 and 2.8mm. To yield useful findings on tyre behaviour in wet weather, however, the surface must be absolutely flawless and meet the highest standards as regards evenness and resistance to deformation, for the film of water must have a uniform depth over the entire area with no breaks. Quite a challenge for contractor Reece Albert, Inc., but one which they mastered effortlessly with technology from VÖGELE. After all, the company had already worked on the Continental Proving Grounds with its SUPER 2100-2 several times in the past.
Maximum precompaction by the paver
The existing pavement was first of all removed to a depth of about 12.5cm. Once a spray seal had been applied, the SUPER 2100-2 with an Extending Screed laid 4.5cm binder course over a pave width of 4.5m, followed by a wearing course, 2.5cm thick, over the same width. To ensure that the mix could be compacted to the particularly high degree of 92 – 97% demanded by Continental, the came in the TP2 version with tamper and two pressure bars. Using high compaction technology with pressure bars driven by pulsed-flow hydraulics, the VÖGELE screed yields the highest degree of precompaction achievable by a paver. This, in turn, lays the basis for durable asphalt pavements resistant to deformation. In Uvalde, the pavement density was tested whenever 500 tonnes of asphalt had been compacted – and met all the specified requirements.
Maximum evenness required
For this job, evenness was another prime concern for Continental: a deviation of no more than 3mm was permitted over a distance of 3m, in both longitudinal and transverse directions. To meet with such stringent requirements, other factors, such as air temperature and the temperature of the mix, too, had to be taken into account. As to machine technology, contractor Reece Albert, Inc. also opted for highest precision, selecting NIVELTRONIC Plus®, the VÖGELE System for Automated Grade and Slope Control. In order to monitor the paving process and ensure a perfect result, the paver was fitted with a Big MultiPlex Ski on the right-hand side to scan the base onto which to lay the asphalt. On the left-hand side, an US ski scanned the already paved strip. In this way, the paving crew was able to ensure that even the slightest deviation from the exacting requirements was instantly detected and corrected.
German technology makes the grade
The result was a tour de force in all respects. Chris Cornell, Business Development Officer at Reece Albert, Inc., was delighted with the German equipment: “The evenness we achieved with VÖGELE High Compaction Technology, in particular, was beyond anything we’ve achieved in the past.” Thanks to this precision, Conti can once again count on highly accurate test results.
Job Site Details
Rehabilitation of the “Vehicle Dynamic Assessment Pad” at the Uvalde Proving Grounds, USA
Length of section: 244m
Width of section: 244m
Pave width: 4.5m
Layer thickness: binder course 4.5cm
wearing course 2.5cm
Special mix in accordance with the client's specifications
SUPER 2100-2 with AB 600 Extending Screed in TP2 Version
HAMM Tandem Roller HD+ 120