2018. 05. 11..

One of last year’s key investments was related to pavement structure diagnostics: Colas Hungária Technology Directorate extended its fleet with a Swedish-made KUAB device capable of measuring dynamic deflections.

The trailer-mounted machine is used for determining the load bearing capacity of pavement structures by measuring the vertical deformation (deflection) on the surface in response to falling weights. The dynamic effect is simulated by dropping a pre-set weight (50 kN) from a given height onto the four-segment disc that has been placed on the pavement surface. As an important difference from conventional static tests, the applied loads are limited in time (15-22 msec), which requires high-precision measuring devices for determining momentary loads and deflections.

Beyond mere condition assessment, the most frequent application of the device is the pre-renovation testing of road beds’ bearing capacity, which provides a basis for designing the new pavement structure. Parameters of the deflection recess caused by dynamic loads provide an efficient support for investigating the condition of pavement layers. This way, the generated parameters are more exhaustive than the ones based on conventional static deflectometers, and allow for further processing with the help of modern computer technology