Components reuse in the building sector – A systematic review

© The Author(s) 2020. The final, definitive version of this paper has been published in Rakhshan, K., Morel, J.-C., Alaka, H., & Charef, R. (2020). Components reuse in the building sector – A systematic review. Waste Management & Research, 38(4), 347–370 by Sage Publications Ltd. All rights reserved. It is available at: https://doi.org/10.1177/0734242X20910463.Widespread reuse of building components can promote the circularity of materials in the building sector. However, the reuse ofbuilding components is not yet a mainstream practise. Although there have been several studies on the factors affecting the reuse ofbuilding components, there is no single study that has tried to harmonize the circumstances affecting this intervention. Through asystematic literature review targeting peer-reviewed journal articles, this study intends to identify and stratify factors affecting thereuse of components of the superstructure of a building and eventually delineate correlations between these factors. Factors identifiedthroughout this study are classified into six major categories and 23 sub-categories. Then the inter-dependencies between the barriersare studied by developing the correlation indices between the sub-categories. Results indicate that addressing the economic, socialand regulatory barriers should be prioritized. Although the impact of barriers under perception, risk, compliance and market subcategoriesare very pronounced, the highest inter-dependency among the sub-categories is found between perception and risk. Itsuggests that the perception of the stakeholders about building components reuse is affected by the potential risks associated with thisintervention.Peer reviewedFinal Accepted Versio

Micromorphological description of vernacular cob process and comparison with rammed earth

International audiencePast builders have developed very low-embodied energy construction techniques optimizing the use of local building materials. These techniques are a source of inspiration for modern sustainable building. Unfortunately, this know-how was orally transmitted andwas lost as earth construction fell into disuse during the 20th century in European countries.The absence of written documents makes necessary to use an archaeological approach in orderto rediscover these construction strategies. Micromorphological analysis of thin sections collected in earth building walls was used for the first time to describe cob construction tech-nique and highlighted several typical pedofeatures allowing to clearly identifying this process.Finally, a first comparison of the cob and rammed earth micromorphological features permitted to identify two key factors to distinguish these two techniques, the manufacturing state (solid or plastic) and the organization of the material in the wall

Assessing the performance of earth building materials: a review of recent developments

After being almost abandoned in Europe at the end of the Second World War, raw earth is currently regaining the interest of civil engineers and architects worldwide. Raw earth (unfired earth) displays very interesting thermo\u2010hygro\u2010mechanical properties, which can contribute to the reduction of the environmental impact of buildings not only during construction but also during service life. Nevertheless, one of the main reasons preventing dissemination of raw earth into mainstream construction practice is the lack of commonly agreed protocols for assessing engineering performance. In this context, the RILEM Technical Committee 274\u2010TCE is critically examining current experimental procedures to propose appropriate testing methods that could be adopted as standards. The present paper summarizes the main challenges faced by the committee and describes some of the existing procedures for measuring the engineering properties of earth materials. The main issue identified by the committee is that laboratory protocols do not accurately reproduce field conditions. The representativeness of laboratory samples is also questionable due, for example, to different degrees of material homogeneity with respect to the field. Finally, the paper identifies some possible routes to reduce the discrepancies between laboratory testing and field conditions in relation to the thermo\u2010hygro\u2010mechanical characterization of earth materials

Barriers to implementing the circular economy in the construction industry:A critical review

To facilitate the adoption of the circular economy (CE) in the architecture, engineering and construction (AEC) sector, some authors have demonstrated the potential of recent designs that take into account the sustainable management of an asset’s end-of-life (EOL), providing an alternative to the dominant designs that end with demolition. However, there is no review of the literature that encompasses a large range of sustainable designs in the current CE context. This paper provides a critical review of journal papers that deal with the barriers to implementing sustainable designs and approaches to the EOL management of assets that have the potential to fulfil the principles of the CE. Eighteen approaches related to prefabrication, design for change, design for deconstruction, reverse logistics, waste management and closed-loop systems were found. Through an analysis of the barriers that are common among these 18 approaches, we classified them into six different categories (organisational, economical, technical, social, political and environmental). Two Sankey diagrams illustrate the interrelation between the barriers, their categories and the 18 approaches. The diagrams clearly show that most of the barriers are common to multiple approaches and that most of the barriers relate to organisational concerns. The study gives a detailed map of the barriers that would help stakeholders from the AEC sector develop strategies to overcome the current obstacles in the shift to a CE

Upper-bound solution for the stability of stone-facing embankments

An upper-bound solution for stone-facing embankments is developed to assess the stability of this type of structures. The embankment is treated as a cohesionless granular material whereas the facing is considered as composed of discrete stone blocks, laid dry one on the top of the other, complying with a Mohr-Coulomb interface law. This enables the assessment of the stability of the structure, solely resorting to its geometry, unit weight, and the friction angles of the embankment and facings. The model is finally used to assess the stability of an existing rockfill dam in the Pyrénées (France). Comparison with Distinct Element Method results and parametric analyses prove the robustness of the model on this case study

Assessing the two-dimensional behaviour of drystone retaining walls by full-scale experiments and yield design simulation

International audienceDrystone walling is a widespread form of construction that utilises local materials. It has received growing interest over the past few years, owing to the recognition of its rich heritage in the framework of sustainable development. However, the growth of dry masonry has been slowed by the lack of scientific evidence proving its reliability. The authors have previously established a model based on yield design to assess drystone wall stability. This theoretical approach has been supplemented by field experiments on full-scale drystone retaining walls that were backfilled until failure with a cohesionless soil. These field experiments followed a first set of experiments in 2002-2003 in which the walls were loaded using hydrostatic pressure. The aim of these experimental programmes was to achieve better understanding of drystone masonry behaviour under loading, and of its failure mode. The present paper consists of a comparative analysis of these theoretical and experimental results, and provides a richer understanding of drystone retaining wall phenomenology. Further perspectives on this work are presented in the conclusion

ECO-MODELES : UNE METHODE D'AIDE A L'ECO- CONCEPTION DE BATIMENTS DURABLES

Aujourd'hui, un grand nombre de secteurs économiques sont influencés par une forte préoccupation de durabilité due au changement climatique et à l'augmentation du coût de l'énergie. Cette inquiétude a emmené les acteurs de la construction de bâtiment à améliorer leurs stratégiques. En effet, nous pouvons noter la quantité considérable d'édifices dénommés « environnementaux » ce qui illustre la tendance actuelle de l' évolution de la conception architecturale. Cependant, il faut convenir que les pratiques restent encore peu instrumentées et relèvent trop souvent du « rafistolage ». Pour répondre à cette situation, plusieurs professionnels et universitaires proposent de réévaluer de manière fondamentale la façon dont des bâtiments sont conçus et produits[1]. Différentes méthodes visant à réduire l'impact des constructions sur l'environnement ont été ainsi mises au point. On citera en particulier LEED aux Etats Unis, BREAM au Royaume Unis, CASBEE au Japon ou encore HQE en France. Il semble qu'elles soient de plus en plus employées [2][3] attestant de la nécessité de développer des outils d'assistance aux pratiques environnementales

First exploratory study on the ageing of rammed earth material

Rammed earth (RE) is attracting renewed interest throughout the world thanks to its “green” characteristics in the context of sustainable building. In this study, the ageing effects on RE material are studied on the walls which have been constructed and exposed for 22 years to natural weathering. First, mechanical characteristics of the “old” walls were determined by two approaches: in-situ dynamic measurements on the walls; laboratory tests on specimens which had been cut from the walls. Then, the walls’ soil was recycled and reused for manufacturing of new specimens which represented the initial state. Comparison between the compressive strength, the Young modulus of the walls after 22 years on site and that of the initial state enables to assess the ageing of the studied walls