The Benkelman Beam Apparatus functions based on the single lever-arm principle. This device must be equipped with a probe that is at least 2.5 meters long, and the extension of the probe is used to depress a dial gauge, which measures the maximum deflection of the pavement surface.

Used to measure the deflection of flexible pavements under the action of moving truck.

STANDARDS

ASTM D4695 • AASHTO T256