french institute of science and technology for transport ... - Ifsttar

Research orientation S_Improving road safety and modernizing transport infrastructure
Asphaltic mixes
Coping with climate change
Asphaltic mixes are very sensitive to temperature.
Present-day changes in the climate therefore mean we
must study their behaviour.
The aim is to develop models that can forecast pavement
creep if average temperatures rise a few degrees above
those observed during the last 30 years.
Current tools for designing mixes and pavements are not able
to take account of this warming, particularly in the case of
slightly special materials such as mixes that contain polymers
or recycled materials or when materials are used in an
unusual way. Several extremely severe cases of rutting have
thus been observed on dedicated rights-of-way for public
transport (Nantes busway, Nancy and Clermont-Ferrand
tyred tram systems). Current pavement design tools do not
consider the specific conditions of slow channelized traffic
that apply in these zones.
The research sets out to develop a method for evaluating
mix performance based on temperature-controlled tri-axial
loading tests that will provide data for a thermomechnical
model for mixes.
This will open the way for an evaluation of the long-term
behaviour of pavement structures and the development of
design recommendations.
Specific types of pavement such as public transport lanes
(Busways), airport pavements and storage platforms all
provide potential applications for the findings of this research.
@ CONTACT
ferhat.hammoum@ifsttar.fr
Wheel-track rutting
on a busway in a bus
stop area.
Wearing course
A fibre-reinforced grooved surface
dressing lengthens service life
In France, the pavement bases on high-traffic roads last
for 30 years or more, while wearing courses have a much
shorter service life of roughly 7 to 10 years.
For this reason, IFSTTAR has started work on developing
a wearing course that maintains its in-service properties much
longer, for 30 to 40 years.
An initial concept was developed in the laboratory between
2005 and 2007. A second project, entitled CLEAN (Long-life
Self-cleaning Environmentally-friendly High Skid-Resistance
Pavement) and which is funded by ANR, improved the initial
concept and led to the development of tools for laying the
material industrially.
We were partnered in the project by the General Councils of
the Loire Atlantique and Sarthe Départements, the CETE Île-de-
France and the firms Calcia, Sika and Pro.sper. This enabled
us to create two experimental construction projects. The first
was a roundabout at Brette-les-Pins (Sarthe) and the second
150 m of wearing course on the RD117 heading towards Saint-
Philbert (Loire Atlantique). In the case of the second project,
very fine grooving was used instead of the planned embedded
chippings and gave satisfactory and what appears to be
durable skid resistance with a noise level that is comparable
to very thin asphaltic concrete. The fineness of the grooving
means motorcycle head shake and aquaplaning are avoided.
Site monitoring has shown that, apart from a few inevitable
teething problems, the grooved surfacing concept seems to
be very promising.
@ CONTACT
thierry.sedran@ifsttar.fr
The surface
of the grooved
fibre-reinforced
hydraulically-bound
surface dressing.
63
THESES
Pierre Aumond_IM
Numerical modelling for environmental
acoustics: the simulation of
meteorological fields and their
inclusion in a propagation model
(13/12/2011)
André Benine-Neto_LIVIC
Trajectory control in curves, towards
the Perceptiv-ESC, through a piecewise
affine approach (15/11/2011)
Farah Homsi_IM
A model to determine the fatigue life
of asphalt mixes under complex loading
(14/12/2011)
Abdourahmane Koita_LEPSIS
Modelling trajectories and their
reliability: application to road diagnosis
(23/03/2011)
Si Hai Mai_NAVIER
A study of the deterioration of urban
railway tracks (02/05/2011)
Rabih Meftah_NAVIER
Multi-scale technique for the dynamic
structural design: application to the
vibrations and noise produced by tyres
(15/11/2011)
Philippe Pecol_NAVIER
Discrete 2D modelling of pedestrian
movements – Application to the
evacuation of civil engineering
structures and interactions between a
crowd and a footbridge (09/12/2011)
Dan Zhao-Orfila_IM
Changes in the pavement skid
resistance: the influence of materials,
ageing and traffic, seasonal
variations (14/10/2011)
Accreditation
to direct
research
Nicolas Hautiere_LEPSIS
Detection and Characterization
of visibility conditions by artificial
vision – Applications to Intelligent
Transport Systems (24/10/2011)
ANNUAL REPORT 2011 ifsttar.fr