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

Expert appraisals
UNEX has marked a European first by performing a safety
assessment of the MAXICITY electric HGV manufactured by
Renault Trucks.
The side impact crash was performed using the large catapult
to propel the barrier and watched by some 40 engineers from
Volvo, Renault Trucks, PVI (a manufacturer of electric vehicle
powertrains), VALENCE (a battery manufacturer), under the
surveillance of SDIS 69 (Rhône Département Fire and Rescue
Service).
Some thirty measurement channels were employed and
analyzed. The lateral impact was obtained by catapulting a
moveable deformable barrier that replicates the impact of a
passenger car hitting the HGV near its batteries.
As a consequence of this first experiment, UNEX was asked
by Renault Trucks to assess a hybrid propulsion system for a
medium-sized HGV. The tests were conducted
successfully using the impact simulation
catapult and the decelerated trolley. Unix
has exploited this expertise in the AZURE
project with Renault Trucks and support
from the LUTB cluster. This project aims
to design a small urban HGV that is completely
optimized for electric operation and
available in a number of different models:
universal chassis-cab, goods transport and
passenger transport. Unix will be responsible
for evaluating the crash-worthiness of this vehicle.
@ CONTACT
patrick.joffrin@ifsttar.fr
Haiti
An audit of a trunk road
77
An expert from IFSTTAR performed an audit on two
rehabilitation projects on trunk roads. This followed on
from the field training part of the highway engineering
course run by the expert in Port-au-Prince at the request
of the EU delegation in Haiti.
Debonding of the mix, which proved to be a defect of
an unusual type, on the road under traffic required an expert
appraisal of the pavement along a length of 60 kilometres.
Investigations revealed problems in the performance and monitoring
of works, which were more or less responsible for the
observed deterioration, but also to shortcomings in the recommendations
and preliminary studies.
An in-depth analysis identified the nature and source of the
problems, assigned responsibility between the project owner
and the contractor (1) , and proposed remedial measures and
a monitoring plan which together proved to be effective. Tools
derived from application of research on the characterization
of binders have revealed highly accelerated aging of the asphalt
in the mix which considerably reduced the service life of
the surfacing and the durability of the pavement, in a country
where strong, tolerant materials should be used that can survive
without maintenance as this is often non-existent.
Additional research would be very useful in order to explain
these phenomena which are caused by the combination of
many factors such as the intrinsic quality of the binder, construction
conditions and, above all, the severe climatic stresses
the pavements have to withstand.
@ CONTACT
yves.brosseaud@ifsttar.fr
Pavement damage.
(1) Studies, design, inappropriate choice of some techniques or the
extremely clayey nature of the soil which is susceptible to shrinkage
cracking.
ANNUAL REPORT 2011 ifsttar.fr