Pavement instrumentation
has recently become an important tool to monitor in-situ pavement
material performance and quantitatively measure pavement system
response to loading and environment. Parameters that need to be
measured in the field include strains, stresses, deflections,
moisture, and temperature. In-situ measurements of these parameters
allow for the development of accurate performance models and the
calibration of mechanistic pavement design approaches. In 1998,
the Virginia Department of Transportation began the construction
of a new test road, the Virginia Smart Road , to be an adaptable
facility for transportation research and evaluation, to serve
the transportation needs for the Montgomery region, and to act
as a tool for regional economic development. The main objectives
of the pavement research at the Virginia Smart Road are the performance
evaluation of different SuperPave TM mixes, the calibration of
pavement response to Falling Weight Deflectometer (FWD) testing,
the evaluation of the feasibility of using Ground Penetrating
Radar (GPR) as a pavement assessment tool, and to predict the
pavement response under different environmental and loading conditions.
The flexible-pavement part of the Virginia Smart Road test facility
includes 12 (heavily instrumented) different test sections. Each
section's length varies between 76 and 117 meters. More than 500
instruments were embedded in the Virginia Smart Road during construction
to quantitatively measure pavement response to vehicular and environmental
loading. Strains and stresses were carefully monitored throughout
the depth of the pavement. Climatic parameters, including temperature,
base and subbase moisture, and frost depth, were also monitored
throughout the depth of the pavement. All instruments were embedded
in the pavement sections during construction. A database of the
measured stresses and strains at different layers of the 12 sections
at the Virginia Smart Road as obtained from different truck loading
tests was developed. The effects of truck speed, tire inflation
pressure, axle load, and axle configuration (single versus dual)
were quantified. Theoretical modeling including the use of existing
software packages and the use of finite element method was evaluated
to compare measure responses to theoretical ones.
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