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Download the two-page presentation of the pavement fatigue carrousel (updated September 2007)  |
Pavement fatigue carrousel
At the beginning of the 1980's, the Roads Division decided
to set up an Accelerated Pavement Test facility for the
sudy of full scale experimental pavements submitted to
heavy traffic levels. This major facility became operational
in 1984 at the LCPC Nantes Test Center. It makes it possible
to reproduce in less than a week up to a full year's truck
traffic load supported by a heavily- trafficked pavement,
with load speeds capable of reaching 100 km/hr.
Tests may focus not only on new pavement structures, but
on their maintenance and reinforcement techniques as well.
The observations and measurements enable the monitoring
under traffic of the fatigue and rutting behavior of materials,
the evolution of pavement surface characteristics, the
tire wear, etc.
The facility experimental site consists in three test
rings, with its central motorization and four arms being
movable from one ring to another within a week's time.
One of the rings has been fitted with a waterproof concrete
pit to ensure hydraulic insulation of the pavement subgrade
with the external water table.
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Pavement fatigue carrousel: overview |
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· Unit assigned responsibility for equipment operations:
Division for Transport Materials and Infrastructures (SMIT),
Pavement Fatigue Carrousel Unit
Sector of activity :
- Roads
Contacts :
Division for Transport Materials and Infrastructures (SMIT)
An exemplary application:
Rutting of wearing courses made with special binders submitted to single axle loads and tridem axle loads
In 1998, the Association of French Highway Companies
and the LCPC jointly conducted, using the Fatigue
Carrousel, a study aimed at comparing the aggressiveness
in terms of rutting from two types of axle configurations:
a the single axle configuration and the triple-axle
semitrailer configuration. The experiment was performed
on four distinct wearing courses: a reference bituminous
concrete and three bituminous concretes made with
low thermal susceptibility binders proposed by oil
companies featuring.
The primary conclusions drawn from this study were:
- the efficiency of
the special binders with low thermal susceptibility
in reducing rutting;
- the satisfactory
reproduction of the behavior observed on the full-scale
tested pavement via the LPC laboratory rutting test
;
- the secondary role
played by the at-rest time in between loadings with
respect to the rutting of surface layers.
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· Technical characteristics:
The carousel
The carrousel is a 750 kW installation composed
of a central tower and four arms, whose ends may
be fitted with various configurations of loads (truck
wheels) of : single or twinned wheels mounted on
either a simple or tandem axle, and single wheels
on a triple axle. Thanks to the considerable arm
length (20 m), the speed of moving loads can reach
100 km/hr.
An original low-stiffness suspension system enables
controlling the loads applied to the experimental
pavements during the entire experience. The loads
may be adjusted between 45 kN on a single wheel
and 135 kN on either a three-axle configuration
with single wheels or a double axle with two wheels
each.
The test
tracks
The site comprises three 110-m long rings with an
average radius of 17.50 m and a width of 6 m. It
is possible to position the loads at different radii
of rotation depending on the arm length.
The third ring has been equipped with a 3-m deep,
10.40-m wide concrete waterproof pit. This set-up
allows controlling the water level in the soil supporting
the experimental pavements. Pumping station makes
it possible to change the water table level during
the experiment in order to reproduce seasonal hydrologic
cycles. Test pavement structures are built using
ordinary road-building equipment (mixing plants,
spreading and compacting machines, etc.).
· Operational since: 1989
· Fields of application
- Pavement fatigue
and rutting tests;
- Validation of pavement
behavior and design models, of equipment method
and specifications ;
- Experimentation
and validation of innovative pavement materials;
- Study of the aggressiveness
of various load configurations of trucks, public
transport vehicles, …;
- Study of f the effect
of traffic on pavement use characteristics, tire
wear, etc.
· Partners:
- Roads Division of
the Ministry of Public Works
- ASFA (Association
of French Highway Companies)
- Road-building contractors
- Oil companies
- European projects
(OECD, RDFP, etc.)
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