LCA allocation procedure used as an incitative method for waste recycling : An application to mineral additions in concrete.This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited.In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t 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.

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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

International audienceThe aim of this article is to develop a methodological approach allowing to assess the influence of parameters of one or more elementary processes in the foreground system, on the outcomes of a life cycle assessment (LCA) study. From this perspective, the method must be able to: (1) include foreground process modeling in order to avoid the assumption of proportionality between inventory data and reference flows; (2) quantify influences of foreground processes’ parameters (and, possibly, interactions between parameters); and (3) identify trends (either increasing or decreasing) for each parameter on each indicator in order to determine the most favorable direction for parametric variation. These objectives can be reached by combining foreground system modeling, a set of two different sensitivity analysis methods (each one providing different and complementary information), and LCA. The proposed method is applied to a case study of hemp-based insulation materials for buildings. The present study will focus on the agricultural stage as a foreground system and as a first step encompassing the entire life cycle. A set of technological recommendationswere identified for hemp farmers in order to reduce the crop’s environmental impacts (from –11% to –89% according to the considered impact category). One of the main limitations of the approach is the need for a detailed model of the foreground process. Further, the method is, at present, rather time-consuming. However, it offers long-term advantages given that the higher level of model detail adds robustness to the LCA results

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

Table 1. Synthesis of LCA literature results related to the cultivation of Spirulina Author Location of the production and culture mode Studied species, culture conditions and considered stages FU and LCA methodology Inventory data Results (GWP )* Remarks Smetana et al.,

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