Researchers are put to the test when required to produce an accurate account of their discoveries...
Scientific results (2004)
- During the 2001-2004 period, LCPC took an active part in the development of performance and durability of concretes.
The bridge of Millau ( 150 KB ) is an example of a direct application. More
- The accident rates in wet weather are definitely higher than in dry weather. This result established in France on the basis of accident data is in agreement with official reports made in other industrialised countries. Degradation of the grip of tyres is a reason, among others, which can explain this over-risk. Indeed, users are not conscious of the important reduction of potential of grip in wet weather. Actual speeds under the two conditions and for various states of wetting with and without rain are not very different. Inter-vehicular distances in the files are practically not modified. Consult four pages ?in French- to know some more ( 150 KB ). More
- It is well-known that the sewer networks are not officially inaugurated, and once put in service they do not constitute a major concern. But it gradually appeared that the effectiveness of treatment was for a good part conditioned by that of collection: the effectiveness of depollution must be apprehended on the scale of the whole of the system (network & plant). LCPC was implied in a new approach of the functional diagnosis of separative networks, its translation into the concept of permanent diagnosis (the MINAUTOR software package) and its extension within the RERAU56 methodology. Consult four pages ?in French- to know some more ( 156 KB ). More
- The concept of model is usually used in physics and mechanics to indicate all the figurations or reproductions which serve the needs for knowledge. The model can be theoretical, numerical or physical and it must reproduce the properties and the behaviour of the object, the structure or the actual work. It is under the direction of J.F. Corté that the geotechnical centrifuge of LCPC was produced. Inaugurated in December 1985 per H. Curien, then French Minister for Research, it thus celebrates its twenty years in 2005. With a radius of 5.5 m, this installation of great ability makes it possible to submit a model of 2 tons to an acceleration of 100g. Consult four pages ?in French- to know some more ( 147 KB ). See also: detailed presentation.
Ten research programs, with plenty of results to report… (2001-2004)
The material included under this heading reveals that LCPC research teams are definitely up to the challenge; a sample of the results obtained from recent work is presented for the laboratory’s ten major programs. These programs were determined in accordance with the priority fields stipulated in the laboratory’s four-year strategy and contract covering the period 2001-2004. This presentation also provides the opportunity to view work performed from a more practical angle and to demonstrate that LCPC "strategic concepts" actually encompass a reality that is both tangible and applicable by the civil engineering community. The first seven programs described stem directly from the five LCPC’s priority orientations and are complemented by the last three more sector-specific programs.
. Investigation, monitoring and diagnoses of civil engineering structures and site analyses
. Durability, maintenance, repair and modification of infrastructure
. Infrastructure and road safety
. Impact of infrastructure on the environment
. Natural hazards, vulnerability of civil engineering structures and networks
. Urban civil engineering
. New materials and new technologies
. Design and construction of civil engineering structures
. Design and construction of transport infrastructure
. Design and execution of geotechnical and underground structures
Scientific results (2003)
- Research conducted within the scope of the RGCU (Urban and Civil Engineering) study network, in partnership with the SITES Company, the SNCF national railway, Université Blaise Pascal and the regional laboratories of both Bordeaux and Lyon regarding the detection of structural damage by means of dynamic testing, has led to both developing a software application run within a Matlab© environment and establishing recommendations that call for implementing dynamic evaluation as a bona fide diagnostic method.
- A major experimental programme, carried out in conjunction with France’s EDF electrical utility on beams that display alkali-reaction phenomena submitted to accelerated aging, has enabled composing a database in order to validate models that serve to re-compute the affected beam structures. A specific module of the CESAR-LCPC software has been validated, and a technical guide on the methodology for managing structures subjected to the internal swelling reaction was published in November 2003.
- The LAVIA project (entitled “Limiter for adapting authorised speed”), financed by both the DRAST and DSCR public agencies and directed by LCPC in partnership with the INRETS transport research institute, the PSA and RENAULT automakers, the Mediterranean and Southwest CETEresearch teams, the DREIF agency and the Accidentology and Biomechanical Laboratory, was able during 2003 to set up the technical experimental system and prepare the evaluation phase on a fleet of ten vehicles operated by some one hundred drivers, as programmed for 2004 and 2005.
- As part of the effort to enhance road safety measures, an infrastructure analysis in association with an accidentology analysis has facilitated the evaluation of accident risk. In this aim, the Lyon and Rouen CETE units developed and then validated “ALERTINFRA”, a software application that allows detecting potentially-dangerous curves and indicating the most frequently-occurring risk factors.
- The Web site of the French Monitoring Office of Recycling in Road Infrastructure “OFRIR” (http://ofrir.lcpc.fr) was launched to the general public on August 1, 2003 and to members of the data exchange club on September 1, 2003; LCPC has run this project in collaboration with the BRGM Mining Agency, the INERIS environmental body and the technical network within the French Public Works Ministry.
- Several techniques and methods for analysing the dynamic behaviour of structures exposed to seismic loadings have been developed within the framework of multi-year research contracts conducted in conjunction with the LGIT geophysics laboratory and many other research organisations: analysis of background seismic noise, the“SISMOA” method for estimating the vulnerability of civil engineering structures, physical modelling in a geotechnical centrifuge, dynamic surveying, etc. This set of research topics has moreover contributed to the growing influence enjoyed by the RAP group (permanent network devoted to accelerometer studies) (http://www-rap.obs.ujfgrenoble.fr) as well as to the adaptations envisaged as part of Eurocode 8.
- Within the scope of RERAU’s (Rehabilitation of Urban Wastewater Networks) 5-6 programme, LCPC coordinated development work on the utility infrastructure management methodology, which serves to prioritise needs in the areas of inspection and rehabilitation, is awaiting publication.
- Two experimental worksites completed in 2003, in partnership with industry professionals, have made it possible to confirm the technical feasibility of technologies resulting from a knowledge transfer from structures to roads; both the “MACES” (self-compacting, hydroextracting structural materials) and “HPC model” (thin sliding layer reinforced with high-performance concrete implemented as a surface layer) projects definitely seem to have rounded out the panoply of French road techniques.
- A reliable and simple method for characterising shrinkage in early-age concretes has been experimented and its repeatability demonstrated. This method has led to defining a conventional testing protocol.
- Within the partnership led by AIRBUS Industries, in conjunction with the STBA and ADP aviation organisations plus LCPC for the purpose of setting up and monitoring an experimental programme conducted on airstrips, the rigid pavement phase launched in 2001 following an initialphase devoted to flexible pavements provided the occasion to host an international conference in November 2003. Results of the fatigue behaviour submitted to various types of jumbo jet landings were presented and enabled anticipating an evolution in the design and sizing methods for concrete airport runway pavements.
- The research carried out within the scope of a CIFRE sponsored doctoral thesis with the main laboratory of the LAFARGE materials group has led to developing an optical method for determining the coefficient of aggregate flattening; the subsequent model, already developed and patent-protected, is applicable to the measurement output of the VDG 40 video-granulometer.
Development and distribution of software and equipment (2003)
- The aim of increasing dissemination of MLPC® equipment, reliance upon licensing agreements for production, marketing and maintenance is being favoured; an initial contract covering mix design equipment was signed on July 1, 2003 with the VECTRA Company.
- Distribution of the "ALIZE-LCPC" software package, which introduces the rational method to mechanically designing pavement structures, was commissioned in 2003 to ITECH. This company has also been assigned to distribute the "CESAR-LCPC" software package, whose Version 4.0
has accounted for some twenty use licenses in the world of industry and around a hundred in academia during 2003 (first year of availability).
- The "COMET2" tension controller, which may be used within the framework of an external control of prestressed concrete structures, was built and experimented.
Scientific results (2002)
- The research conducted by the laboratory’s FDOA
(Structural
Operations and Durability) Division on the dynamic
evaluation of bridges has been pursued within the
framework of the RGCU civil and public works engineering
network, in partnership with the SNCF and SITES organizations, as well as with the University
Blaise Pascal and the Bordeaux and Lyon regional laboratories.
Initial results have already highlighted the potential
of the dynamic structural evaluation to lend a suitable
tool in the investigation, monitoring and assessment
of pavements; the numerical tools derived from this
work have already been programmed into the Matlab”
systems environment.
- A set of research studies focusing on the aging
of polymeric bitumens, performed over the period 1999-2002,
has led to establishing both an original methodology
for examining aging that applies to other multiphase
materials as well and a current state of knowledge
on the evolution of such materials upon implementation
and service startup.
- The PREDIT program entitled Road accidents during
rainy conditions, conducted between 1998 and 2002
in partnership with the automaker PSA
Peugeot Citroën, the SERA-CD
company, METEO
France National Weather Service and INRETS,
has demonstrated the influence of wet road conditions
on pavement adhesion in conjunction with motorist
behavior, thereby confirming the importance of ensuring
a high level of adhesion within heavy traffic zones.
- Research efforts in the area of road noise led during
2002 both to defining a “Long-Term Reconstitution”
method that takes into account the micro-meteorological
characteristics of the study site and to setting forth
the guidelines of a measurement methodology (yet to
be validated) that provides continuous readings of
tire-pavement contact noise.
- The research completed from 1998 until the end of
2002, in coordination with the LPC network of laboratories,
the INERIS national institute on industrial environment and risks
and local quarry/mining operations agencies, on abandoned
underground mines has served to compile the following
methodological guides:“Geophysical location of
underground cavities”, “Stability diagnosis”
and “Incorporation of marl pits in development
projects”.
- The 1998-2002 program on measuring pollutant flows
within urban wastewater, performed in cooperation
with a number of engineering schools, universities,
the GEMCEA
Research Group (for the Evaluation of Water and
Wastewater Composition Measurements) plus several
LRPC regional laboratories, has enabled devising a
series of calibration and evaluation methodologies
(instrumentation for measuring turbidity, particle
size and velocity) as well as proposing measurement
validation and synthesis methods for a sewer system.
- The year 2002 also ushered in new research initiatives
thanks to Magnetic Resonance Imagery, which revealed its capacities
for the study of complex flow patterns in the field
of fluid mechanics applied to concrete mixing.
- A guide on the Protection of concretes by application
of products on external faces has given rise to a
research program that got underway in 1997 within
the LPC network, in conjunction with the Laboratory
of Historical Monuments and the SETRA Roads and Highway Technical Research Agency.
- The capacities of the pavement fatigue carrousel facility have been extended
thanks to completion of a waterproof casing underneath
one of the ring set-ups; this installation now makes
it possible to study the influence of hydric conditions
on the durability of flexible pavements with granular
compositions.
- Full-scale testing conducted in partnership with
the LIRIGM Interdisciplinary Laboratory of Geology and Mechanics
Research (University of Grenoble), along with the SNCF, SCETAUROUTE and BIDIM Geosynthetics organizations, has served to validate
a design method for geosynthetic-based reinforcements
of platforms within zones containing potential cavities.
Software and hardware developments
(2002)
- Version 4 of the CESAR LCPC computational software package, which integrates
the new CLEO 2D and CLEO 3D preprocessing and post-processing
programs, was finalized at the end of 2002; this version
is now being distributed by the firm Itech.
- A new device for measuring the complex modulus of bituminous macadam overlays
was certified in April 2002, in association with a
measurement system for “Symetra” trapezoidal
specimens; this set of equipment serves to complete
the family of bituminous macadam study instrumentation.
