Automatic Levelling in Road Construction

The fulfilment of today’s demand for particular pavement course thicknesses and a particular evenness in the construction of road surfacing is one of the main task set road building equipment. This aim can be reached through the use of electro-hydraulic control facilities for the working units of the corresponding construction machinery. The subject of this paper is to deal with the automatic control technique used for the levelling systems on the bulldozers, graders, milling machines, asphalt pavers and concrete finishers. Starting out from theoretical considerations, the experience gained from practical operation of the levelling system employed nowadays will be described, as well as the limits set to these systems.