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Existing territorial life cycle assessments (LCAs) consider all activities in a given geographical area, defined as the foreground system, but cannot lead to operational decisions. In product scale LCA, the foreground system is defined as the part of the system directly controlled by an actor and is thus more adapted to compare possible scenarios within a decision perimeter. The present paper uses that concept applied to a geographical area. The developed method consists of five steps: (a) definition of the foreground material flow analysis (MFA) or LCA system corresponding to the decision perimeter; (b) territorial MFA; (c) geo-location of activities and downscaling of territorial flows to individual activities; (d) calculation of local transport distances; and (e) calculation of LCA impact indicators. The case study concerns the management of primary and secondary resources of basic quality aggregates (BQAs) in the Loire-Atlantique department (France) in 2012. Our results show that the amount of recycled cement concrete is only 7% of total consumed BQAs, although 90% of cement concrete demolition waste (CCDW) is recycled. The environmental impacts are importantly related to off-site activities. Local impacts are mainly driven by the transport of aggregates. For land planning, a concentration of fewer recycling facilities with high authorised production capacities in main cities, close to where CCDW is mainly produced, would divide transport needs in half and thus considerably reduce environmental impacts.

International audience; The end-of-life of buildings is increasingly involved to improve waste management and environmental concern of the construction sector. A Life Cycle Assessment (LCA) model is suggested in this paper to holistically estimate environmental impacts of the end-of-life of any building. The model allows to consider on site works (i.e. machines, workers …), 40 waste types and 7 waste treatments, with potential benefits from recovery. The model, which is parametric, can be easily instantiated for any building and for different end-of-life strategies (e.g. demolition or deconstruction, reuse or recycling). It can be used as a decision aid by engineers to plan the deconstruction or demolition of a building considering the environmental impact of this process. This model is applied to different real-life cases. The results show that the impacts and therefore the best scenario (i.e. the one that minimizes the environmental impact) are highly case-dependent; for example, deconstruction does not perform better than demolition for all criteria and case studies. This demonstrates the value of a parametric model that can be effective and easily applied to different buildings and strategies.

The global challenge of large-scale climate change mitigation requires action also in the building and construction sector. From a life cycle perspective, and considering the mitigation timeframe, the issue of reducing embodied GHG emissions is gaining attention. Effective ways to reduce embodied GHG emissions have been proposed by the use of fast-growing, bio-based materials, due to carbon sequestered in the biomass. Another promising, yet largely under-explored option is to harness the environmental potentials and low embodied GHG emissions of earth-based materials for building construction. Earth construction dates back from 10,000 to 8000 BC and has been derived in many vernacular construction techniques. More recently, some earthen techniques have been modified, using stabilizers, mainly cement and lime, to increase strength and water stability. The objective of this article is to compare existing literature performed on the LCAs applied to various earthen construction techniques and seek for key factors. Transports as well as binder stabilizations are very influent on the results. Climate, nature of local soil, and geographical context are very influent on functionalities of buildings, mix design and transports, themselves influencing environmental impacts. According to design choices and local context, earthen construction is not always better than concrete. This means that no universal solution can be recommended with the LCA of an earthen wall. The solution has to be adapted to the local context. All references comparing walls material to conventional materials at the building scale, find better environmental performances of earthen walls compared to fired brick walls. However, a full comparison between earthen construction and conventional materials should account for the use phase: combining LCA models with thermal and durability models is a key research issue. Finally, it certainly would be useful to seek for solutions with best environmental performances in a local context, accounting for the nature of soil, the building's functional requirements as well as geographical and cultural specificities. Such an approach would ensure to lower environmental impacts but represents a drastic change in current construction practices. Whereas today building materials are standardized in order to fit with construction working practices, this paradigm shift would require to adapt construction working practices to the local material and context. As earthen construction is today, in many countries of the world, a re-emerging technique, and new professional practices are yet to be established, it seems possible to make this paradigm shift happen. Certainly, in the current context of the need to substantially reduce building-related GHG emissions, there is still strong potential in earth construction techniques for both research and building practice.

Based on the RILEM Technical Committee 274-TCE work, this paper is a discussion of the remaining engineering challenges faced by earthen architecture. The assessment of earth material performances requires the development of appropriate procedures and standards. This is discussed in particular for the characterisation, hygrothermal behaviour, mechanical behaviour, and durability of earth materials. One other important challenge, since one of the main advantages classically put forward, is its ecological performance, is a proper assessment of life cycle assessment of earth materials, elements and buildings. Moreover, the paper develops why the approach to earthen construction must be different compared to the dominant construction materials, to preserve its ability to contribute to the ecological transition in the construction sector. In particular, the needs of using local soils, with an architectural approach coping with the limits of the materials, and developing an architectural optimisation to preserve the earthen materials multifunctionality rather than selecting a sole property to be maximised. Lastly, the findings of the paper can be used to develop a holistic approach to earthen construction to foster the development of new earthen architecture projects.

CO2 emissions from cement production currently represent around 6% of global CO2 emissions. However, cement concrete absorbs CO2 from the atmosphere because of carbonation (i.e., penetration of atmospheric CO2 inside bulk concrete). Carbonation has beneficial effects on the mechanical resistance of cement concrete. However, carbonation also has adverse effects because it provokes a decrease in pH that favors later corrosion of reinforcing bars and thus reduces service life. Current European standards provide recommendations concerning reinforcing concrete covers, but these are not based on actual service-life durations. Thanks to a previously developed carbonation model combined with sensitivity analysis and LCA, we compare Climate Change indicators of 1 m2 of reinforced concrete cover over a 100-years service life exposed to XC4 conditions in Madrid, obtained on one hand by using current standards and on the other hand with concrete-cover depths calculated with our carbonation model. Our results show that cement strength class is a key parameter to both increase durability and decrease climate-change impacts. When the carbonation model is used to optimize both durability and climate-change impacts, it drives to considerable and significant improvements. Finally, climate-change indicators predicted from our carbonation model are not linearly linked to carbon intensity of cements, which is a current argument of so-called "green cements." The values of indicators presented in this article cannot be generalized: They mainly depend on the geographical location. However, the model and key action levers are general. Using high cement strength classes and low water-to-cement ratios allows use of lower concrete-cover depths and thus save amounts of concrete compared to the standard. This generates an important benefit in terms of climate-change impacts for identical service lives and improved mechanical resistance. Thus, considering the huge impact of cement and construction industry on climate change, we plead for a revision of standards which, instead of thresholds based on simplified models, should provide certified tools enabling the best design for every situation. This article met the requirements for a gold/gold JIE data openness badge described at http://jie.click/badges.

To identify action levers that improve the environmental balance of Spirulina manufacture, this work presents an LCA study of a modelled Spirulina production coupled with Morris sensitivity analysis on the model parameters. The study concerns a hypothetical cultivation surface of 388.5 m2 in open and covered raceway ponds (ORP and CRP) under greenhouse located in the city of Nantes in France. Several environmental indicators were evaluated, though GWP (global warming potential) was chosen for deep results discussion. Results showed a large variability of GWP (global warming potential) indicator for both culture systems (from 15.5 up to 67.3 kg eq. CO2/kg biomass dw) depending on the three most impacting parameters (the use of a thermal regulation system for the culture medium, the low setpoint temperature regulation and the annual production period). Moreover, for both ORP and CRP systems, GWP reduction per kg of biomass is reached by avoiding all impacts related to thermal regulation (i.e. thermal energy, heat pump, etc.) and simultaneously yielding high biomass productivity. Hence, annual cultivation should be extended as long as suitable solar conditions are available for the growth of microalgae (high and long irradiation and high ambient temperature). Finally, both ORP and CRP systems reached similar annual production but have different GWP impact since (i) their needs of thermal energy are opposite in warm and cold periods and (ii) the impact related to the CRP infrastructure is almost twice the impact of the ORP infrastructure due to the CRP reactor cover.

Construction and demolition waste (CDW) generation, identified as a priority stream by the European Commission, accounts for approximately 25 to 30% of all waste generated in the European Union. According to local specificities (e.g. regulations, waste management organization) best environmental options may differ for transforming waste into new resources. Five oral presentations were given in the session which focused on innovative modelling initiatives combining LCA with complex models in order to improve knowledge for more sustainable urban construction waste management. During the discussions, all participants agreed that re-use or recycling mass performance is a weak and unsufficient indicator for assessing waste management systems. There is an important need for better characterizing stocks and predicting nature and quality of output flows. Geospatialized data combined with Material Flow Analysis was the methodology identified and used by the research community.

The aim of this study is to develop a new design procedure for the durability of the Reinforced Concrete (RC) structures in aggressive environments. The study approach developed here includes: (i) a qualitative analysis phase to characterize the design parameters and environmental exposure conditions of RC structures; (ii) a quantitative analysis phase, to establish the relationship between service life and design parameters and environmental exposure conditions using the service life prediction model firstly, and then to determine the most influential design parameters on service life using sensitivity analyses; and (iii) a final design phase, to design RC structures using some favorable values of the most influential design parameters firstly, and then to compare the service life thus obtained with that of RC structures designed using a standardized approach. An application is also proposed on simulated RC structure exposed to carbonation in Madrid (Spain). This RC structure follows the recommendations of the European standard EN 206–1 for XC4 exposure class. The sensitivity analysis results are discussed in detail including influence trends, importance ranking, non-monotonic effects and parameter interaction influences. The most influential design parameters obtained are cement strength class ( f c e m ), water-to-cement ratio ( W / C ) and cement type ( C E M ). By using W / C of about 0.4, f c e m of about 52.5 MPa and CEM I cement type instead of their limiting value as recommended by EN 206–1, the service life of the RC structure is significantly improved.

Carbonation processes cannot be ignored as regards durability and service-life of new concrete structures, and their correct understanding and quantification are essential for maintenance and repair works on existing structures. This paper initially presents a new meta-model developed to calculate carbonation front depth based on the analytic solution of Fick's first law. The only input data required by this non numerical model are: (i) material variables (concrete mix design, maximum nominal aggregate size, cement type, and chemical composition of cement type CEM I and cement density); (ii) technological parameters (initial curing period (t(c))); (iii) environmental parameters (ambient temperature (1), relative external humidity (RH) and CO2 concentration in the air ([CO2](ext)). Consequently, this model is fully suitable for the prediction of carbonation depth in the case of new reinforced concrete structures, for which these required parameters are well-known. The meta-model is validated using data from the literature on short and long-term natural carbonation exposure conditions. Most of the experimental data concern CEM I, CEM II, CEM III cement types, and CEM I additives (fly ash (FA)) with various water to cement (W/C) ratios and t(c). The meta-model is also compared with two already available models: Papadakis' model and Yang's model. The three model predictions are compared with the corresponding values found in the literature. The results confirm that the prediction of the new meta-model proposed here for estimation of carbonation depth is the most accurate in every case.

International audience; This work investigates the discrete kernel approach for evaluating the contribution of the variance of discrete input variables to the variance of model output, via analysis of variance (ANOVA) decomposition. Until recently only the continuous kernel approach has been applied as a metamodeling approach within sensitivity analysis framework, for both discrete and continuous input variables. Now the discrete kernel estimation is known to be suitable for smoothing discrete functions. We present a discrete non-parametric kernel estimator of ANOVA decomposition of a given model. An estimator of sensitivity indices is also presented with its asymtotic convergence rate. Some simulations on a test function analysis and a real case study from agricultural have shown that the discrete kernel approach outperforms the continuous kernel one for evaluating the contribution of moderate or most influential discrete parameters to the model output.

International audience; The complexity of the Life Cycle Assessment (LCA) method requires many subjective choices throughout the procedure, which make decision making difficult and LCA results insecure. Our approach consists in combining life cycle thinking and sensitivity analysis to provide information to the actor of a foreground system within a product's life cycle. For any parameter of a foreground system, the trends and quantified influence on impact categories are systematically compared to determine the most effective action levers for actors controlling the process. This approach has been previously applied to a single actor, the farmer, in a case study of hemp crop production. In this study, we introduce a second life cycle actor: the industrial producer for transformation of hemp straw into insulation products for buildings. The relationships between farming and industrial actors are examined and demonstrate that industrial actors have action levers limited to climate change and energy consumption. Only a joint action of both actors can allow further reduction of climate change and energy consumption impacts. Nevertheless, the farmer action alone can allow reduction of other environmental impacts such as human toxicity or ecotoxicity.

Current environmental and economical circumstances accelerate the developments of new concrete constituents. Whereas the process technology impacts the mix-design strategy, it seems obvious that manufacturing process is prone to evolutions. This article presents a method to compare environmental and economical consequences of different technological solutions on the basis of the influence on the cement consumption needed for a given concrete performance. Case study is the choice of dry batch or central mixed concrete production systems for a ready mixed concrete production. The theoretical difference in cement consumption is estimated by considering that the water content fluctuation is by far the dominant factor governing the truck to truck variation. The addition of a mixer is effectively found to contribute to cement reduction. Environmental comparison is performed using an EADT indicator (Environmental Amortization Duration Time) defined in the article, and testing various environmental data. The EADT for energy consumption, released CO2 and particles are found below 6 years, in the whole range of tested environmental data for an annual production of 40,000 m3 yr1, with 2 m3 mixer for the central mixed concrete plant. The NOx and SO2 EADT results are found sensitive to the releases of the steel plant. The financial amortization duration time corresponding to the purchase of a mixer, is found less than 2 years. Although the chosen application case is simplified, these results encourage further research.

The purpose of this paper is twofold: to investigate the problems involved when performing an environmental assessment of various pavements structures and to establish the method applied to solutions proposed by official French guidelines. This assessment will be performed by employing the life cycle assessment (LCA) methodology specifically adapted to road pavements through a parametric environmental evaluation tool developed by LCPC: ERM (elementary road modulus). The paper will also detail the assessment methodology using this same ERM method. The issues of resources conservation and waste allocation will be examined for the case of blast furnace slag (BFS) recycling. Special focus will be placed on the sensitivity of environmental indicators as regards to the waste allocation procedure implemented in the ERM. Two distinct mass ratios (0% and 20%) of steel production have been assigned to BFS and tested on indicators results as hypotheses H1 and H2, respectively. Classical indicators have been calculated using a simplified model to allocate output flows into several impact categories. Results show that the structure using BFS contributes to saving binder extracted from natural resources, yet also consumes a larger mass of natural aggregates. All indicators except for toxicity were found to be very sensitive to the choice of H1 or H2 hypotheses.

Hot mix asphalt industries are required to meet airborne emissions thresholds, yet only a few types of emission measurements are available. This study is therefore aimed at evaluating the influence of operating parameters on airborne emissions at the plant stack, especially Gaseous Organic Compounds (GOC), in addition to identifying both the best mixing conditions and bitumen influence through laboratory testing. Emission measurements have been performed for a given set of production conditions, and results highlight significant changes in emission flows. CO2, SO2, NOx and GOC all seem to be correlated with combustion intensity and energy consumption, whereas CO tends instead to be associated with combustion efficiency. Laboratory GOC variations exhibit monotonic increases with temperature; at the plant level, these effects are concealed by combustion scattering due to burner adjustment. Flow assessment is provided at the plant for each pollutant along with its dispersion.

An experimental program has thus been undertaken to collect environmental data and assess the potential environmental impacts from a pavement containing Reclaimed Asphalt Pavement (RAP) in varying proportions, by means of the Life Cycle Analysis (LCA) technique. This paper presents the methods and results inherent in the Impact Assessment component of the LCA standard (ISO 14 043). Except for the toxicity and ecotoxicity impact indicators, the entire set of computed indicators reveals a trend of decreasing potential environmental impacts with an increasing recycling rate. The trend derived for the majority of computed indicators is found strongly correlated with the transport process. Results depend upon various data sources, whose quality is not known with precision that could lead to biasing indicator results. Simplifying hypotheses are recalled in the conclusion.

The dilatational rheology of adsorbed films of β-lactoglobulin has been studied at the air–aqueous solution interface and the n -tetradecane–aqueous interface using a Langmuir trough apparatus employing a pulse change in interfacial area. The effect of the addition of the non-ionic surfactant C 12 E 6 to films adsorbed from 10 −3 wt% β-lactoglobulin at pH 7 and 30°C was also examined. The surfactant appears to bind to β-lactoglobulin with a low molar ratio (one surfactant molecule per protein molecule), but this and/or co-adsorption has significant effects on the dilatational moduli. Films exhibit higher dilatational moduli at the oil–water interface compared to the air–water interface and show a stronger dependence on the surfactant concentration at the oil–water interface. At around equimolar ratios of protein and surfactant there is a slight maximum in the dilatational moduli, more noticeable at the oil–water interface, though separate measurements also indicated a slight enhancement of foam stability in this region. At higher surfactant concentrations there is a more marked decrease in the dilatational moduli to similar values for both types of interface. Moduli measured at strains up to at least 5% appear to be considerably non-linear.

Depuis le stade des études préliminaires jusqu’à la réalisation des travaux, un projet routier fait l’objet de décisions successives (opportunité, budget, tracé…), selon une procédure progressive et réglementée. Cette succession de choix s’insère dans un faisceau de contraintes environnementales, techniques et financières. Ceci rend le processus décisionnel complexe, du fait notamment de la multiplicité des acteurs potentiellement impliqués. Dans ce contexte, la contribution de chercheurs peut consister à fournir des méthodes, permettant d’apporter un éclairage sur les conséquences potentielles en terme de développement durable, des décisions successives prises depuis la conception d’un projet routier jusqu’à sa réalisation. Dans cette perspective, une analyse des critères décisionnels propres à chacun des acteurs au sein du processus décisionnel, est nécessaire. L’objectif de cet article est d’analyser sur quels enjeux généraux reposent les critères décisionnels intervenant dans les différents choix successifs d’un projet routier. Il s’agit d’une part d’effectuer l’examen détaillé du processus décisionnel régi par des éléments factuels imposés par la réglementation, et d’autre part de mieux appréhender les critères non réglementaires, propres à chaque acteur sous la forme de témoignages. Sur la base de la synthèse réalisée, une discussion propose ensuite de mettre en perspective l’analyse effectuée au regard des enjeux environnementaux et de concertation. L’analyse montre la difficulté à définir une liste de critères décisionnels relatifs à la prise en compte des enjeux du développement durable. D’autre part, la réflexion menée met en lumière la meilleure prise en compte des enjeux environnementaux lorsqu’une démarche de concertation est menée en amont du projet, ce qui va au-delà du simple cadre réglementaire et reste à l’initiative de la maîtrise d’œuvre ou de la maîtrise d’ouvrage. Cependant cette démarche s’avère souvent limitée aux enjeux locaux, et intègre peu les enjeux planétaires, notamment le réchauffement climatique et l’épuisement des ressources naturelles.From preliminary studies to the execution of road works, a road project is submitted to a succession of decisions, following a regulated procedure. This succession of choices is bordered by environmental, technical and financial constraints. Thus, the decisional process is complex, especially because various and numerous actors are implied. In this context, contribution of research can consist in elaborating methods that can inform on potential consequences of successive decisions, in terms of sustainable development. This expects an analysis of decision criteria that are specific to each actor inside the decisional process. The objective of this paper is to analyze on which general stakes the decisional criteria are based. First, factual elements of the decisional process are extracted from regulations. Then, non regulated criteria are investigated through the collection of expressions of different actors. A discussion put the obtained results in the perspective of environmental and consultation stakes. The analysis shows the difficulty to express a list of explicit decisional criteria that respond to the stakes of sustainable development. Environmental stakes are found better considered when a consultation approach is performed at the very beginning of the project. This consultation can only be decided by the client or the project manager, because this goes further than strict regulation demands. However this approach is often limited to local stakes, whereas planetary environmental stakes, such as climate change or natural resources depletion, are often neglected.

396 p.; International audience; Eco-design aims at improving the production process of a single product and eco-design practitioners often consider environmental performances of a product as a part of its initial functionalities. Only the use of LCA can quantify environmental performances. Because of its comparative nature, using LCA for eco-design requires comparing a new solution to an existing one. In the construction sector, materials are often considered as an eco-design variant. The use of a construction material is undeniably linked to its intrinsic properties but the link between these properties and its functions is not always obvious because several physical scales are nested (materials, in construction elements, in constructed objects). Using LCA in that frame means to compare various materials on the basis of identical fulfilled functions. The purpose of this article is to suggest a generic approach for using LCA to eco-design materials for construction. This approach takes into account the multi-functionality of materials, the "nested scales" of products, and the lack of knowledge at the early stages of design. The proposed approach might be the most convenient accompanying approach that should occur all along the design process from the material to the constructed object.

Avec la prise de conscience de la menace liée aux émissions de CO2, les matériaux biosourcés sont de plus en plus utilisés dans le bâtiment en remplacement des matériaux courants. Les matériaux biosourcés sont des produits qui, au-delà de leurs intérêts fonctionnels, sont susceptibles d’offrir des avantages environnementaux en limitant l’utilisation de ressources fossiles non renouvelables et en réduisant le bilan des émissions de gaz à effet de serre par absorption du CO2 nécessaire à la croissance des plantes. Le comportement d’un matériau de construction peut être étudié à différentes échelles imbriquées (échelle du matériau, de l’élément de construction et de l’objet construit) et pour différentes fonctions (l’isolation thermique ou phonique, ou encore la portance). Ce travail fait état des connaissances sur les matériaux biosourcés et des besoins pour permettre de comparer, en utilisant la méthode d’analyse de cycle de vie, leurs performances technologiques et environnementales à celles des matériaux classiques en prenant en compte les aspects multi-échelle et multi-fonctionnel. La méthodologie proposée pour la prise en compte de ces aspects dans la méthode ACV permet d’évaluer a priori les besoins en connaissances et le niveau de complexité d’une évaluation environnementale destinée à comparer des matériaux pour la construction.

International audience; Purpose The classification step is systematically neglected in the calculation of LCIA indicators: for several direct contribution of one pollutant to several impact categories, the distribution between these impact categories is not accounted. The proposed approaches of non-redundant classification are based on the probability that an emitted substance and its chemically degraded forms are involved into several environmental impacts. Methods Two types of repartitions are examined in this paper: i) one, called equiprobable classification, based on identical probability of contributions to several impact categories, and ii) and one, called zone classification based. Both methods are based on a classification coefficient alpha and require categorization of chemical pathways (reactive, suspensive, direct, indirect). The first method, the equiprobable classification, is a quick method that allows avoiding multiple counting of pollutants. The second method, the zone classification method is based on two steps: i) the first step requires defining an impacted zone around the source, inside which the emitted chemicals are expected to majorly diffuse or spread; ii) in the second step, the score of the chemical is set according to the occurrence of the chemical target inside the impacted zone. Results Both methods are applied on a case study of NOx emissions in Paris. Results highlight big differences (33% to 47%) when using or not the classification coefficient. Coefficients calculated using equiprobable or zone classifications are of the same order of magnitude except for indirect contributions. Discussion The zone classification method is compared to other site specific LCA methods. The choices of impacted zone and of chemical targets are discussed with the aim to meeting paradoxical constraints: local parameters must be sufficiently detailed in the majority of cases, but generic enough to avoid time consuming researches. The availability of data is also discussed as well as the possibility to include indirect impacts into the environmental system. Conclusions The conceptual frame suggested for classification of pollutants into emission-based impact categories, is a first approach for a scientific question that was raised in the 90's. equiprobable classification is easy to apply but not entirely satisfying from a physical and chemical background. Zone classification relies upon the specificity of emission compartments, and occurrence of chemical targets in the impacted zone. It still needs improvements. It has important consequences in terms of data collection, system boundaries, and only practise will show its actual feasibility.

Waste recycling avoids waste landfilling and all associated releases. It also allows for saving nonrenewable resources. However, the new commercial interest for waste can be seen as a shift in their status from waste to co-product. This has important consequences for environmental load allocation between the different industrial products (and co-products) in industrial plants. In this paper, the specific case of cement has been studied. Actually, to reduce the environmental impact of cement and concrete, industries have been engaged over the last 10 years to increase the replacement of Portland cement by alternative cementitious materials that are principally industrial waste or by-products. In this study, the environmental impacts of two different Supplementary Cementitious Materials (SCM), blast furnace slag and fly ash, are considered using Life Cycle Assessment methodology through a study of the influence of different allocation procedures on environmental impacts of SCM in concrete. Three allocation procedures are tested. In the first one, which is the current practice, no allocations are done. As for the two others, the environmental burdens of the system are respectively associated with the relative mass and some current economic values of the co-products and products. The results are discussed according to the specificity of the cement substitution products (SCM) and the driving forces that are identified for the use of these co-products. Then, a description investigation of another allocation procedure is proposed based on the fact that it is not the relative economic value that permits to evaluate the environmental burdens but the contrary. This last allocation procedure could be generalised for other waste recycling and be used as a regulation tool between the different industrial branches.

The degradation of refractory chemicals in water requires chemical oxidation by hydroxyl radicals. Among the systems that may be used to generate OH(o), the Fenton's reagent consists of the mixing of ferrous iron and hydrogen peroxide. Even though this system is very simple, the oxidation of an organic compound is difficult to control and the ferrous iron regeneration is limited. Very recently, electrochemical systems have merged that allow the electrochemical production of ferrous iron and/or hydrogen peroxide, thereby allowing the generation of OH(o). So a simple electro-Fenton system has been used and tested for its efficiency in producing hydroxyl radicals. Atrazine was chosen as a model organic compound as its reaction with OH(o) has been extensively studied. Comparison with the classical Fenton system gives advantage to the electrochemical system, due to a more thorough oxidation of atrazine.

The degradation of chemicals in water is commonly performed using chemical oxidation. In case of refractory compounds, hydroxyl radicals have to be involved for their degradation. Several systems may be used to generate OH°, such as the ferrous iron-hydrogen peroxide system (Fenton’s reagent). However, when this reagent is prepared by mixing the two constituents, the oxidation of an organic compound is difficult to control and the ferrous iron regeneration is limited. So, very recently, electrochemical systems have merged that allow the electrochemical production of ferrous iron and/or hydrogen peroxide, thereby allowing the generation of OH°. In this paper, the efficiency of a simple electro-Fenton system in degrading chemicals in acidic medium is shown. Atrazine was chosen as a model organic compound. In addition, the electrochemical system compared favorably with the classical Fenton’s reagent under similar conditions, as it allowed a more thorough oxidation of atrazine.

The planet is in a particularly worrying state of degradation of ecosystems, depletion of resources, demographic tension and a climate emergency. The decoupling of the consumption of raw materials with economic activity is a relevant action lever. By reducing the pressure on the scarcity of raw materials, the circular economy can participate in the fight against climate change. Although recycling alone cannot solve resource depletion, it is essential to implement solutions to regenerate the materials present in our waste. However, the current organization of the end-of-life sector does not seem to meet the needs of the world economy.The first challenge in deploying recycling solutions in the circular economy is based on evaluating the performance of recycling scenarios. The proposed methodology is based on several analytical tools: Material Flow Analysis (MFA), Life Cycle Assessment (LCA) and Life Cost Costing (LCC) in a technical reference framework based on the evaluation of environmental technologies (ETV). This work applies in partnership with the company MTB. Three performance axes were chosen: technical, economic and environmental.This multi-criterion assessment, integrated into the MTB design process, allows communication in the form of key performance indicators (KPI). By providing additional performance indicators it is possible to quickly quantify the eco-efficiency, to support decision-making by designers during the development of the recycling pathway., La planète se trouve dans un état de dégradation des écosystèmes, d’épuisement des ressources, de tension démographique et d’urgence climatique particulièrement préoccupant. Le découplage de la consommation de matières premières avec l’activité économique est indispensable. En réduisant la pression sur la raréfaction des matières premières, l’économie circulaire peut participer à la lutte contre le dérèglement climatique. Bien que le recyclage ne puisse solutionner seul l’épuisement des ressources, il est indispensable de mettre en œuvre des solutions pour régénérer les matières présentes dans nos déchets. Or l’organisation actuelle de la filière de fin de vie ne semble pas répondre aux besoins de l’économie-monde.Le premier challenge pour déployer des solutions de recyclage en économie circulaire repose sur l’évaluation de la performance des scénarios de recyclage. La méthodologie proposée repose sur plusieurs outils d’analyse : analyse de flux de matières (MFA), Analyse de Cycle de Vie (ACV) et Analyse de coûts (LCC) dans un cadre technique de référence basé sur l’évaluation des écotechnologies (ETV). Ce travail s’applique en partenariat avec la société MTB. Trois axes de performances ont été retenus : technique, économique et environnemental.Cette évaluation multicritères, intégrés dans la démarche de conception de MTB, permet une communication sous la forme d’indicateurs clés de performances (KPI). Ces indicateurs supplémentaires permettent de quantifier rapidement l’éco-efficience d’un scénario, pour accompagner la prise de décisions des concepteurs lors de la construction de l'offre et du développement des solutions scénarios de recyclage.

The implementation of a method for the conduct of cohousing operations is the subject of this study. Our partner is social housing company that is a property developer and a rental manager. One of his objectives is to develop a new offer: cohousing. The objective is to involve the future occupants in the design process of their residence in order to guarantee their satisfaction.This approach has many similarities with participatory design methods that have demonstrated their benefits for the quality of the manufactured products as well as for the user satisfaction. In the French Housing sector, cohousing operations are uncommon and generally carried out by residents who want to avoid property developers.Several arguments explain this gap between the two sectors. Unlike manufactured products, the constructed object is unique. The design of a building must adapt to local specificities and its production environment, the construction site, is under uncertainty.Moreover, on public projects, the law orders the separation between owners, designers and builders. This constitutes an obstacle to the sharing of good practices and strengthen coordination mechanisms based on informal communication. Construction operations are therefore considered non-repeatable. A second argument that explains the low number of cohousing projects lies in the cultural specificities of the sector. Occupant satisfaction is rarely measured and the gap in terms of knowledge and communication with professionals is huge. Unlike manufacturing industry, the formalization of a participatory process is in contradiction with the practices of a sector where projects are not repeatable and therefore not very formalized. We then demonstrate the importance of formalizing the participatory process that must be carried out, and then alert the consequences of the involvement of the inhabitants. We are interested in the phenomenon of resistance to organizational change. In our context, the management of organizational change seems to constitute a pertinent answer to this phenomenon.The objective of this doctoral thesis is therefore to define and then test a methodology for Cohousing projects. First, we propose a process modelling by defining the roles of each stakeholder on the different stages of a real estate operation. We explain the level and the topics of participation to obtain the satisfaction of the future occupants. In order to analyze the implementation of our recommendations, we develop a model for the formalization of the cohousing process integrating the using constraints of the professionals. Secondly, we are building a process of organizational change management in order to prevent the difficulties caused by an upheaval in the conventions shared between professionals.Our proposal is tested on two successive cohousing operations. On the basis of participant observation, interviews and questionnaires, we highlight the positive impact of participatory design on satisfaction. In a second step, we compare the accompanying steps with the change implemented and their effects on the two operations. We find that the better the change management is conducted the less the incidents on collaboration or communication issues are significant. Consequently, we confirm the relevance of a cohousing project management methodology that combines the involvement of the inhabitants in a participative design process and the organizational change management., Les travaux présentés traitent de la mise en place d’une méthode pour la conduite d’opérations d’Habitat Participatif. Ils ont été menés avec une société de logement social qui assume les rôles d’aménageur, de promoteur et de gestionnaire locatif. Notre partenaire souhaite développer une nouvelle offre : l’Habitat Participatif. L’objectif est d’impliquer les futurs occupants dans l’opération de construction de leur résidence afin de garantir leur satisfaction.Cette approche présente de nombreuses similitudes avec la conception participative qui a démontré ses bénéfices pour la qualité des produits manufacturés, comme pour la satisfaction des utilisateurs. Dans le Logement, les opérations d’Habitat Participatif sont très rares et généralement menées par des habitants désireux de se soustraire des promoteurs immobiliers.Plusieurs arguments expliquent ce décalage entre les deux secteurs. Contrairement aux produits manufacturés, l’objet construit est unique. La conception d’un bâtiment doit en effet s’adapter aux spécificités locales et son environnement de production, le chantier, est incertain. De plus, sur les projets publics, la loi impose la séparation entre propriétaires, concepteurs et constructeurs. Cette situation constitue un obstacle au partage de bonnes pratiques et renforce des mécanismes de coordination basés sur de la communication informelle. Les opérations de construction sont donc considérées non-répétables.Un second argument qui explique le faible nombre de projets d’Habitat Participatifs réside dans les spécificités culturelles du secteur. La satisfaction des occupants n’est que rarement mesurée et le décalage en termes de connaissances et dans la communication avec les professionnels est particulièrement marqué.Contrairement à l’industrie manufacturière, la formalisation d’un processus participatif s’oppose aux pratiques d’un secteur où les projets ne sont pas répétables et par conséquent peu formalisés. Nous démontrons par la suite l’importance de formaliser le processus participatif qui devra être mené, puis alertons des conséquences de l’implication des habitants. Nous nous intéressons ainsi au phénomène de résistance au changement organisationnel. Dans notre contexte, l’accompagnement des individus au changement organisationnel semble constituer une réponse pertinente à ce phénomène.L’objectif de cette thèse est donc de définir puis tester une réponse méthodologique à l’Habitat Participatif. En premier lieu, nous proposons un processus type en définissant les rôles de chacune des parties prenantes sur les différentes étapes d’une opération immobilière. Nous explicitons le niveau et les thématiques de participation nécessaires pour obtenir la satisfaction des futurs occupants. Afin d’analyser la mise en œuvre de nos recommandations, nous développons un formalisme de modélisation des processus intégrant les contraintes et de manipulation inhérentes aux professionnels. En second lieu, nous construisons une démarche d’accompagnement des individus au changement pour prévenir les difficultés causées par un bouleversement des conventions en vigueur entre les professionnels.Notre proposition est testée sur deux opérations participatives successives. Sur la base d’observation participante, d’entretiens et de questionnaires nous mettons en évidence l’incidence positive de la conception participative sur la satisfaction. Dans un second temps, nous comparons les démarches d’accompagnement au changement mises en place et leurs effets sur les deux opérations. Nous constatons que mieux l’accompagnement est mené moins les incidents sur des questions de collaboration ou communication sont significatifs.En conséquence, nous confirmons la pertinence d’une approche de conduite des projets d’Habitat Participatif combinant l’implication des habitants dans une configuration de conception participative et l’accompagnement des professionnels au changement organisationnel.

The purpose of this PhD thesis is to establish an eco-design method based on Life Cycle Assessment, that should allow identifying action levers specific for each economic actor of the life cycle of a product, for improved environmental performances. Life Cycle Assessment was coupled with two methods of sensitivity analysis in five steps: (i) definition of objectives and system, (ii) modeling calculation of inventory and impact indicators with different approaches according to foreground and background sub-systems, (iii) characterization of parameters using a typology specific to possibilities of control of the considered economic actor, (iv) application of two sensitivity analysis methods (Morris and Sobol) and (v) results interpretation in order to identify potential efficient improvements.The approach was applied on the hemp concrete insulation product, including agricultural production, industrial transformation of hemp fibers, and use of hemp concrete as a thermal insulator for buildings.The approach provides potential technological scenarios improving environmental performances for each single economic actor of the product’s life cycle.Performing the method presently requires additional information, but will probably be paid back in the future by driving more robust choices for a given product.; L’objectif de ce travail de thèse est d’établir une méthode d’éco-conception basée sur l’Analyse de Cycle de Vie, qui doit permettre d’identifier des leviers d’actions environnementaux propres à chacun des différents acteurs économiques intervenant dans le cycle de vie d’un produit. L’Analyse de Cycle de Vie a été couplée avec deux méthodes d’analyse de sensibilité, suivant cinq étapes décrites dans le mémoire : (i) la définition des objectifs et du système, (ii) la modélisation du calcul de l’inventaire et des indicateurs d’impacts avec des approches différenciées en premier et arrière-plan, (iii) la caractérisation des paramètres utilisés avec une typologie définie selon les possibilités d’action de l’acteur économique concerné, (iv) la réalisation successive de deux méthodes d’analyse de sensibilité (Morris et Sobol) sur le modèle défini, (v) l’interprétation des résultats en vue de proposer des pistes efficaces d’amélioration. L’approche établie a été appliquée au cycle de vie du béton de chanvre, avec l’étude des étapes de production agricole, de transformation des fibres de chanvre et d’utilisation du béton de chanvre comme isolant thermique dans le bâtiment.L’approche permet d’identifier des scénarios technologiques potentiels, permettant d’améliorer les performances environnementales, pour chacun des acteurs du cycle de vie du produit. Mettre en œuvre cette approche actuellement nécessite un surcroît d’informations, mais présente un gain à long terme car elle permet d’effectuer des choix robustes pour un produit donné.

The purpose of this PhD thesis is to establish an eco-design method based on Life Cycle Assessment, that should allow identifying action levers specific for each economic actor of the life cycle of a product, for improved environmental performances. Life Cycle Assessment was coupled with two methods of sensitivity analysis in five steps: (i) definition of objectives and system, (ii) modeling calculation of inventory and impact indicators with different approaches according to foreground and background sub-systems, (iii) characterization of parameters using a typology specific to possibilities of control of the considered economic actor, (iv) application of two sensitivity analysis methods (Morris and Sobol) and (v) results interpretation in order to identify potential efficient improvements.The approach was applied on the hemp concrete insulation product, including agricultural production, industrial transformation of hemp fibers, and use of hemp concrete as a thermal insulator for buildings.The approach provides potential technological scenarios improving environmental performances for each single economic actor of the product’s life cycle.Performing the method presently requires additional information, but will probably be paid back in the future by driving more robust choices for a given product.; L’objectif de ce travail de thèse est d’établir une méthode d’éco-conception basée sur l’Analyse de Cycle de Vie, qui doit permettre d’identifier des leviers d’actions environnementaux propres à chacun des différents acteurs économiques intervenant dans le cycle de vie d’un produit. L’Analyse de Cycle de Vie a été couplée avec deux méthodes d’analyse de sensibilité, suivant cinq étapes décrites dans le mémoire : (i) la définition des objectifs et du système, (ii) la modélisation du calcul de l’inventaire et des indicateurs d’impacts avec des approches différenciées en premier et arrière-plan, (iii) la caractérisation des paramètres utilisés avec une typologie définie selon les possibilités d’action de l’acteur économique concerné, (iv) la réalisation successive de deux méthodes d’analyse de sensibilité (Morris et Sobol) sur le modèle défini, (v) l’interprétation des résultats en vue de proposer des pistes efficaces d’amélioration. L’approche établie a été appliquée au cycle de vie du béton de chanvre, avec l’étude des étapes de production agricole, de transformation des fibres de chanvre et d’utilisation du béton de chanvre comme isolant thermique dans le bâtiment.L’approche permet d’identifier des scénarios technologiques potentiels, permettant d’améliorer les performances environnementales, pour chacun des acteurs du cycle de vie du produit. Mettre en œuvre cette approche actuellement nécessite un surcroît d’informations, mais présente un gain à long terme car elle permet d’effectuer des choix robustes pour un produit donné.