Paving roads of the future with 3D Machine Control

The project: A2 EP12

As part of the A2 EP12 Bellinzona rehabilitation project, the CasCa consortium (composed of Mancini & Marti SA, Walo Bertschinger AG, Savioni Attilio SA, Pizzarotti SA, Giudicetti SA, F.lli Somaini SA) joined forces to enhance soundproofing via new and existing guards and undertaking approximately 6.2 km of pavement reconstruction with Open Porous Asphalt, a modern sound-absorbing asphalt mix.  This asphalt mix also increases safety on the road substantially as it reduces the spray behind cars when heavily raining. 

A symphony of coordination: enhanced efficiency with multiple pavers

At the heart of this success story lies the intricate coordination and synchronisation of various paving machinery guided by 3D machine control technology. The traditional challenges associated with manual paving methods, characterised by labour-intensive processes and potential inaccuracies, were transcended through the precision that the Leica MC1 pave solution offers.

By synchronising the efforts of multiple paving machines, the construction team achieved an unparalleled level of accuracy and efficiency. The left and right pavers were equipped with  3D machine control systems but guided with just one active mast and a total station. The middle paver acted as the mediator, matching its height with the leading pavers on both sides.

In addition, utilising multiple total stations for auto leapfrogging allowed the pavers to hand over automatically between two reference points, ensuring continuous and precise operation when the free line of sight is blocked or the maximum distance from the total station to the prism is exceeded. 

This dynamic interaction between the left, right, and middle pavers, working in harmony to maintain consistent height alignment, eliminated the need for complex string line setups. This not only streamlined the process but also reduced the number of required total stations, resulting in significant cost and resource savings. In addition, the Leica MC1 paving system allows unique flexibility in operation, enabling the use of 3D sensors on one side and 2D sensors on the opposite side or the combination of 3D sensors for orientation and 2D sensors for elevation control.

Navigating constraints: overcoming space and safety challenges

One of the standout challenges faced in the Bellinzona project was the constrained space due to noise barrier walls and crash barriers. Unlike conventional string lines, which would have been impractical and posed safety risks for workers, 3D machine control technology flawlessly navigated these obstacles. This forward-thinking approach not only enhanced safety but also ensured a smoother workflow, further contributing to the acceleration of the paving process.

Using advanced measurement tools and software technology, surveyors can easily assess factors such as pavement thickness, surface smoothness, and cross-slope consistency. By employing technologies like laser scanning and GPS-based systems, surveyors capture accurate data on elevation variations and deviations from intended slope angles. This comprehensive analysis allows them to determine whether the asphalt pavement aligns with the required specifications, ensuring durability, safety, and optimal performance of the roadway.