Benkelman beam

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The Benkelman beam is a measuring device in road construction that can be used to determine the load-bearing capacity of a road pavement. The measurement method is based on the fact that, as a result of a wheel load, a depression is created on the road surface and springs back again after the wheel load has been removed.

Measurement method

A two-axle truck with twin tires on the rear axle is driven onto the area to be examined (measuring point) (control wheel load 50 kN). The probe arm of the Benkelman beam is placed on the road surface between the twin tires of a wheel and the measured value is recorded. The truck then moves five meters forward and the reading on the Benkelman bar is read again.

Results

The maximum spring back results from the difference between the two measured values. However, the surface temperature must always be taken into account and the measurement results corrected to 20 ° C if necessary. In addition to the maximum springback, the measurements can also be used to determine the influence line of the depression. In this case, the measurement is carried out electronically and recorded within very short distances while the vehicle moves away from the measurement point.

literature

  • E. Straube, K. Krass: Road construction and road maintenance . Erich Schmid Verlag, Berlin 2005, ISBN 3-503-09067-3 , p. 296 ff .