Rolling dynamic deflectometer

The RDD developed by the Center for Transportation Research at the University of Texas at Austin and the current version are a modification of a Vibroseis truck originally used for oil exploitation (Bay and Stokoe 1998). 

The dynamic load system (a combination of static and dynamic force, hence servo-vibrating load) is located at the middle of a two-axle truck. The applied dynamic load is applied to the pavement surface via two rollers placed parallel to the track wheel axles. The deflection is 

The operating speed of the RDD is 5 km/h, which is a disadvantage when it is compared to other rolling profilometers operating at much higher speeds 60 to 80 km/h. 

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Moving (moving Rolling dynamic deflectometer (RDD) Vibrating mass 5... 

Figure 16.52 TPAD rolling dynamic deflectometer. (From Texas A M Transportation Institute [TTI], Using New Technologies to Sohe Old Problems, Texas Transportation Researcher, Vol. 49, No. 4, http // www.tti.tamu.edu, 2003.)...

Bay J.A. and K.H. Stokoe. 1998. Development of a Rolling Dynamic Deflectometer for Continuous De flection Testing of Pavements. FHWA/TX-99/1422-3. Austin, TX Center for Transportation Research, The University of Texas at Austin. 

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