Precisely milled substrate as a basis for safe, durable streets

Author: Ilona Bihlmayer

The civil engineering and road construction sector is facing ever more challenges. When it comes to motorway construction, public authorities require shorter build times to keep traffic jams and congestion to a minimum. Other challenges include the increasing number of heavy good vehicles due to the international movement of goods, increasing commuter traffic, the general increase in the number of individual cars on the road, and the size and weight of those cars.

For all these reasons, companies in the civil engineering and road construction sector need to be especially diligent to ensure roads are safer and more hard-wearing, and that they last longer. The planning parameters and target values for roads given by those who commission the builds should, in theory, guarantee the optimal run-off of surface water, good distribution of loads, and durability.

Roads that are tougher and safer thanks to digital measurement solutions

Using digital measurement solutions in road construction helps to transfer these target values into precise actual values on the ground. For this reason, Mr Stahl, head of the surveying department at LEONHARD WEISS decided to use a digital solution from Leica Geosystems for the milling work on the renovation of the superstructure of the German A70 autobahn (BAB A70), to speed up the work and ensure it is precise.

For this project, the state of Bavaria, through the North Bavarian Motorway department, has provided the planning data and the target values to the construction company in a design guide. When it comes to renovating a road, milling off the existing surface layer is an important step. An accurately milled substrate is a prerequisite for delivering the planed asphalt base layer as detailed in the design guide with precise cross slopes and gradients.

Digitisation should increase efficiency and precision without impeding progress

“The aim of this project is to use 3D profile milling to create a base with exactly the right profile, which we can then build on,” explains Mr Stahl. He needs a system that is “ready to use quickly, so that the construction process is not brought to a standstill.”

When selecting a measurement system for the team and Stefan Stahl, easy-of-use and minimal effort required in upgrading the milling machine were also important factors.

The entry-level, GNSS-supported milling solution from Leica Geosystems met all those requirements and so Stahl opted for the Leica iCON site Milling Pilot.

As LEONHARD WEISS was already using the Leica iCON iCG70 and iCG60 construction rovers, the CC80 construction controller, and the iCON site-field software, introducing the Milling Pilot System was seamless. The iCON site software, developed specifically for positioning tasks in the construction industry and which runs on all Leica iCON-GNSS hardware, was particularly helpful here.

“Our team found it easy to operate the Milling Pilot. The software is intuitive, the milling process was displayed graphically and it helped us to set the milling depth accurately,” stressed Stahl. A brief on-site introduction to the system was all that was needed for the entire milling team to be able to use the system.

An all-round digital solution for civil engineering and road construction

Projects like these are increasingly being handled digitally. In this case, the existing site was surveyed digitally by an engineering firm and the data was then transferred into the iCON software.

The target values from the design guide were then loaded into the software, and the delta, the section that needed to be milled away, was calculated. The 2-step preview of the target and cross slope values on the main set points along the road enabled consistent milling with no unevenness.

The software’s visualisation function meant that the error-prone spray-on marking process was not necessary and it saved time and costs compared to the manual preparation process. In road construction, costs are also incurred when additional layers need to be applied if the milling has gone too deep. This is also avoided by the increased precision the system provides.

Simple installation

The iCON site Milling Pilot simply requires an iCON-GNSS smart antenna, a CC80 controller and the relevant software. Positioned on the top of the milling machine, the antenna, in this case the iCON gps 70 T, sends GNSS correction data to the controller. This data is displayed graphically by the software.

Impressive service and support from Leica Geosystems

Initially the LEONHARD WEISS team rented the system to see if it was the right solution for them. Shortly afterwards, they invested in a system of their own. “During the testing phase and with the installation of our own system, the service and support we received from the Leica Geosystems team in Germany was immensely helpful,” says Stahl.

Stahl went on to say that, “the Leica Geosystems team set up an individual installation just for us whereby the system was powered with electricity directly from the machine so there would be no need to charge batteries.”

As a long-standing customer of Leica Geosystems, Stahl knows he can rely on Leica Geosystems for support with a wide range of projects and, in conclusion, said that “he would recommend the iCON site Milling Pilot without hesitation for its precision and ease-of-use. This, and all the other systems from Leica Geosystems that I have used, makes work on the building site easier every day. The Leica service team is always there to answer our questions and help us optimise our processes.”

Within a short space of time the entire milling team at LEONHARD WEISS GmbH & Co. KG was familiar with operating the iCON site Milling Pilot.

The iCG70T is impressive, not just as a construction site rover with precise GNSS data, but also on top of a milling machine.

The 2-step preview enables precise milling results without unevenness

The Leica iCON CC80 controller uses the iCON site software to graphically display the milling depths prescribed.