Discrete numerical simulation of civil engineering processes and materials for Life Cycle Assessment

Eco-construction Chair of excellence - GeM laboratory - Nantes University
Job Description: 


Taking into account environmental aspects in the buildings and civil engineering sector, requires a demanding. This pluridisciplinary approach can be applied for various application domains such as the reduction of the environmental impacts of materials and structures, the durability control of constructions, notably in marine of fluvial environments, the improvement of the quality of life…
In that context, favorable to innovation and technological advances, Scientifics, contracting owners and industrials associate today, to constitute an excellence research and education chair in civil engineering and eco-construction.
This chair is issued from a partnership between Nantes University, through its projects foundation, the urban community of Saint-Nazaire, the business and industry chamber of Nantes - Saint-Nazaire, three industries (VINCI Construction France, Charier TP, A.I.A – Architectes Ingénieurs Associés), the French Federation of Buildings – Pays de la Loire and the regional Federation of Public Works.
The pluridisciplinary activities of the chair will benefit from a 4 years funding, used for research and education.
The employees of the chair are attached to the GeM laboratory (Research Institute in Civil Engineering and Mechanics) and will provide lectures in Nantes University of civil engineering.
The objectives of the chair are:
- to create an excellence pole with an international visibility in civil engineering and eco-construction,
- to favour the accounting for sustainable development stakes in the construction sector,
- to contribute to high level innovative education in civil engineering.


Life Cycle Assessment (LCA) is a methodological framework aiming at quantifying environmental effects of products using indicators.
The scientific objectives of the chair are to reliabilize the LCA methods applied to eco-design of construction materials (for buildings or civil engineering).
A production system in LCA can be structured as an oriented graph, with nodes or black boxes (vertices) linked by dynamic interactions (edges), inside a system. Each node can be linked to other nodes inside the system, to itself, and can receive and generate interactions from and with the exterior of the system. Some interactions are desired and represent the objective(s) of the system (i.e. the product), whereas other interactions are not desired (i.e. negative effects of the system on the environment).
Even if this represents a complex system, LCA models are presently based on a simplified approach where each node (which represents a technological process) is in a non dynamic linear interaction with other nodes and with the outside of the system. This simplified approach is somehow efficient but reaches some limits on some points.

First point : when a node has several objectives (in or out flows), one needs to distribute the non desired environmental effects between these objectives. This is allocation in LCA vocabulary. The current methods consist of affecting a coefficient, based on an arbitrary choice, to each of these objectives. The proposed research activity consists of developing calculation methods of the distribution coefficients by opening the black box or node. This node is itself a sub-system of nodes in interaction, and the organization of this sub-system is variable. To obtain coefficient at the upper scale, a stochastic approach is necessary to characterize system typologies, that conduct to stable allocation models.
Proposed application: modeling of a quarry process for construction aggregates production

Second point: LCA implies to consider the service life of products (that are objectives of the system). In construction, the considered product is the construction material. This step of the method requires a scale change, because the material fulfils one or several function(s) (the word “function” is to understand in a general meaning, i.e. “the role of the product in an ensemble”) inside a construction element (assembled materials). The functions of a construction material can be conceived as a set of physical magnitudes, scalable constraints, classifications, or boolean variables. The values attributed to these functions can be altered with time (notion of durability). When the material is inside a construction element, it is subjected to random events, variables in their frequencies and intensities. The objective is to develop models of the alteration of function(s) within the service life period, of a construction element, from the alterations of its components properties.
Proposed application: service life scenarios of a construction element submitted to an aggressive natural environment (choice of materials and of aggressions to determine).

Third point : LCA implies to consider the end of life of products. In general, when a material is recycled, it is considered to substitute to natural resource. A generic substitution rate is calculated whatever are the recycling practises. These highly depend on various constraints such as regulations, existing stocks, the adequacy between offers and demands, technological feasibility… The problematic can also be represented as a network of nodes located in a territory, of which interactions will depend on constraints listed above. Relevant substitution rates can be calculated according to the system typology.
Proposed application: modeling construction materials flows (natural and recycled) inside a local territory (i.e. région Pays de la Loire)

Requirements for candidates
The candidate is a computer science and/or discrete mathematics researcher with the following aptitudes:
Statistical methods Monté Carlo, typology Required knowledge and experience
Generic softwares Matlab (notably Simulink) Required knowledge and experience
Agent Based Modeling Required knowledge
Graphs theory Required knowledge
Process simulation softwares and Material Flow Analysis (MFA) ProSim, Umberto Knowledge and/or experience is advantage
LCA methods and softwares GaBi, SimaPro or OpenLCA Knowledge and/or experience is advantage
English Good level (read, written, spoken)
French Read, spoken

The candidate must be motivated by research in a pluridisciplinary in team, by the management of PhD and students, and by education. He (she) must prove high quality in pedagogy to be able to exchange with his (her) colleagues from other disciplines, and in international and scientific opening. The candidate must be willing to integrate the applicative dimension of his (her) work that is important for the chair’s patronage. The candidate must be able to beneficiate from research networks in his (her) own discipline. The staffing of a technician is envisaged. Previous experience of research with private companies is an advantage.

Required diploma: PhD
Type of contract: definite term, 1 year renewable for 3 years
Education charge: around 100 hours per year
The candidate must send a detailed CV (publications, congress, any other useful information), a application letter, and a scientific project proposition (3 pages maximum), before the 15th of Septembre 2012 to:
anne.ventura@ifsttar.fr and abdelhafid.khelidj@u-nantes.fr
Auditions of pre-selected candidates are scheduled in October

Job Categories: 
Universities and colleges
Deadline for Application: 
Sep 15 2012