Twenty Wirtgen group construction machines in operation on site
“Faced with complex technical requirements and an ambitious schedule, the project management organization, the consortium Consorcio Autopista del Coral, elected to use the reliable world market leading machines from the Wirtgen Group,” explained José Luis Matallana from Resansil RD S.A., the Wirtgen Group dealer in the Dominican Republic. A total of 20 Wirtgen Group machines got to work in December 2010. Eighteen months later, the new “Autopista Del Coral” section was completed as planned.
Strong Wirtgen Surface Miners and Kleemann impact crushers
The first construction phase involved eight surface miners and two impact crushers. Thanks to their flexible all-terrain mobility, the surface miners were able to make maximum use of their capacity. The four 2100 SMs and the four 2200 SMs milled off limestone in a single pass, producing the grain size of 0 to 4” required for its reuse for the road extension – an economical process. For the 2200 SM mines between 150 and 200 m³ of limestone per hour while the thickness of the cutters only drops by 0.01 mm per cubic metre. “Not only did using the surface miner enable us to dispense with the expensive and time-consuming drilling and blasting of larger lumps of rock, it levelled the surface of the ground perfectly, preparing it for the following steps, and saved resources, too,” said Matallana. The Mobile Impact Crusher MR 130 Z EVO processed more of the limestone, also crushing it down to the required grain sizes directly on site. Crushing 450 m³ of limestone per hour, it ensured that the new base material for the further expansion of the highway section was available in next to no time. As a result, there was no need to procure the required material from a mine located 40 km away, avoiding high transport costs.
Technologies from Vögele and Ciber ensure a perfect paved result
The excellent preparation of the soil meant that the three Vögele pavers could start paving the lower base course immediately. They were supported by the Ciber Cold Mix Plant USC 50 P and the Batch Asphalt Plant UAB 18 E. Producing between 100 and 140 t of mix per hour, the UAB 18 E, for instance, supplied the high-quality paving material without delays. The Vögele SUPER 1900-2 then got to work, performing excellently. The resultant pavement had a remarkable evenness of below 2 m/km according to the International Roughness Index (IRI) and a very high degree of compaction of 88% on a 25-cm-thick asphalt pavement. As a result, the work progressed swiftly, as no further compaction measures were required. The 20-cm-thick lower base course and the 17-cm-thick upper base course were thus quickly paved, each with a width of 6.5 m. A 4-cm binder course and a 3.5-cm wearing course rounded off the pavement of the new traffic route. Wirtgen soil stabilizers and Hamm earthwork rollers had already ensured a perfectly cohesive foundation before the asphalt paving work commenced. In the process, the Vibratory Compactor 3520 took on the work of two ordinary 11-t rollers, being able to compact as much as 1200 m³ of uncompacted 25-cm-thick base course. With their wide range of applications, the earthworks rollers 3520 and 3414 VIO with vibration and oscillation also greatly reduced the amount of rollers required for the project. Hamm Tandem Rollers HD 90 put the finishing touches to the roadway surface – and, needless to say, they achieved ideal compaction values.
Pioneering: Wirtgen Group excels in all areas
By constructing the “Autopista Del Coral” section and extending the entire “Corredor Vial del Este” highway, the local authorities achieved an important milestone in the improvement of their national traffic infrastructure. Traffic safety has been greatly improved, important centres have been linked and travelling times slashed by up to 50%. This will not only benefit locals, but also the tourism trade, the Dominican Republic’s most important industry.