SMB CI - Planning & consulting

Within the framework of conceptual design for a testing site, the dimensions of the high-speed track with its recommended speeds need to be determined accurately. Depending on the shape and size of the plot of land, this results in flatter or steeper curves to ensure the centrifugal force is countered when driving the track.

Over the years, SMB has become an important consultant for automotive manufacturers and their suppliers when it comes to dimensioning and budgeting high-speed tracks, often for the entire testing facility. This applies not only to new construction, but also to the planning and designing of binder and surface course replacements on existing tracks while simultaneously optimising the geometry.

The core issue when designing high-speed curves is the selection of a suitable parabola for the desired track speeds and the appropriate transition curve onto the level track. After checking the conceptional design using driving simulation, detailed planning takes place and the curve data can be copied to the bridge paver’s control menu. For the detailed design, it is important that the working width of the bridge paver and the roller groups are taken into account both in a flat position and at an angle. This includes a sufficiently wide, flat and stable crest path and an equally stable and flat supply path on the inside of the curve which usually is used as the breakdown lane.

For the substructure of the banked curve it is recommended to use, a suitable sub-structure of aggregate is laid in horizontally compacted layers to support the corresponding gradient. The road surface is built on this sub-structure, starting with a hydraulically stabilised sub-base The sequence between laying the fast track and the crest path is selected to ensure that the upper edge joint is of maximum quality. For compaction, vibration rollers with variously shaped drums are used behind the bridge paver. A roller plan determines the areas where the various rollers are used depending on the surface curvature.