In the future, the eastbound and westbound lanes of the A 43 Autobahn near the city of Münster, Germany, will be separated by a poured-in-place concrete safety barrier. The effectiveness and permanence of such construction elements for the passive protection of road users make them the preferred vehicle restraint system, especially on sections of roads with heavy traffic.
The monolithic profile will be paved by an SP 25i using the slipform paving method. The use of AutoPilot 2.0 on this project eliminates the need for the paving crew from VSB infra GmbH & Co. KG to set up a stringline for controlling the machine. They use the 3D control system whenever and wherever possible.
Automatic 3D Control System
Developed by Wirtgen, the control system enables precise, stringless control of slipform pavers. As the system completely eliminates the time and effort usually required for setting up and removing a stringline for conventional machine control, it also reduces project completion times and costs. Instead of this, the machine is guided along a virtual stringline by satellite-aided navigation. This makes the entire workflow faster, more efficient, and, in turn, more cost-effective. At the same time, it also makes the paving of complex geometries such as tight radii or in S-bends, significantly easier.
Working Space and Safety
As is typical for construction projects on major highways like the A 43 Autobahn, the working area offers very little room for the paving crew. Using a stringline in front of the machine in situations like this would limit this space even more. But you won’t find anything like that here! Not unless you take a look at what’s shown on the screen of the AutoPilot tablet. The hand-held control unit displays the course of the virtual stringline and provides precise information to the machine operator at every single point along the predefined track. This also means that there is plenty of free space in front of the slipform paver. Concrete mixers have room to maneuver and can drive right up to the paver to deliver their load. The free space in front of the machine brings the paving crew more room to work in and leads to greater safety on the project site. The absence of a stringline also removes the risk of tripping and injuries as a result of falls.
Planning
The team from VSB infra uses AutoPilot before the actual construction work begins. Relevant points on the project site are recorded with the Field Rover survey pole and form the basis of the digital data model for the generation of the virtual stringline. This eliminates the need for an additional surveyor on the project site.
Implementation
The AutoPilot then takes control of the slipform paver. The machine then works its way along the predetermined virtual stringline with absolute precision. The existing sub-base of the A 43 is sampled by an ultrasonic sensor and used as a reference datum by the machine control system. The result of this is extremely precise paving of the required concrete profile.
Quality Assurance
The AutoPilot also does an important job behind the machine. The Field Rover also enables extremely precise quality assurance measurements of the paved profile in no time at all.
