Tracking particle displacements in unbound aggregate layers of roadways

ABSTRACT

Accelerated pavement tests were conducted on reduced-scale pavement sections under controlled environmental conditions using the model Mobile Load Simulator (MLS11). A unique monitoring system was developed as part of this study to evaluate the response of the pavement sections under rolling wheel loads. The performance of the sections with an increasing number of wheel passes was evaluated by measuring the surface rutting as well as the subsurface displacement of particles within the base layer. The sections were built in modular frames constructed above grade to facilitate access to the particles within the base layer from the sides of the frame. Surface rutting was measured intermittently using an in-house developed laser profilometer. A unique, cost-effective assembly of 30 linear position transducers was designed to continuously track the displacements of artificial particles within the base layer. The displacements, measured with the new system, were found to be particularly suitable to generate horizontal permanent displacement fields and strain fields. Overall, the new developments allowed comprehensive monitoring of the internal response of pavements subjected to wheel loading.

KEYWORDS:

• Particle tracking
• accelerated pavement test
• MLS11
• profilometer
• displacement field

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

S. Subramanian

S. Subramanian is a Ph.D. in Civil Engineering from the University of Texas at Austin, USA. He specializes in the area of geosynthetic-stabilized aggregate base for flexible pavements. He earned his B. Tech. from the National Institute of Technology, Tiruchirappalli (India), and his M.E. from the Indian Institute of Science, Bengaluru (India)

Jorge G. Zornberg

Jorge G. Zornberg is the Brunswick-Abernathy Regents Professor at the University of Texas at Austin. He has over 35 years’ experience in research and practice in geotechnical, geosynthetics, transportation, and geoenvironmental engineering. He earned his B.S. (Hons.) from the National U. of Cordoba (Argentina), his M.S. from PUC-Rio (Rio de Janeiro, Brazil), and his Ph.D. from the U. of California at Berkeley.