The environmental impacts of activities such as raw material extraction, construction of infrastructure, and demolition, place construction as one of the sectors that exert the highest pressures on the environment, society, and economy. Some of the major environmental impacts for which the construction industry is responsible are mineral resource depletion, greenhouse gas emissions, and waste generation. Among the different strategies that exist to decrease such impacts, recycling demolition waste into recycled concrete aggregates has been considered a promising alternative. As such, at present, the literature dealing with the impact assessment of recycled aggregate concrete structures is very extensive. Therefore, the objective of this article is to present a critical view of the state‐of‐the‐art in terms of sustainability assessment of recycled aggregate concrete structures, taking a holistic perspective by considering environmental, social, and economic impacts.
Sustainability has increasingly become key in universities, as the objectives of sustainable development are essential to establish policies, guidelines and indicators that guide institutions to be more sustainable. This recognition has led many authors to develop methods to assess universities based on their performance in terms of sustainable development. This article presents a review of these methods. The review focuses on identifying existing methods and classifying the methods according to seven characteristics: (1) nature of the data, (2) data collection, (3) scope, (4) level of implementation, (5) pillars of sustainability, (6) university function, (7) country perspective taken, which will allow identifying the differences between methods when assessing sustainability. The seven criteria established for the characterization of the sustainability assessment methods contain a total of 27 sub-criteria distributed among the properties. The main contribution of the study is the analysis of the revised methods through a comprehensive characterization and systematic grouping. In the discussion, the results are examined by looking at the comprehensiveness, heterogeneity and objectivity of the methods reviewed. Together with previous research in the area, this study highlights the need to continue deepening the design of sustainability assessment methods with standardized criteria.
Digital fabrication with concrete (DFC) is fast becoming an attractive alternative for components (i.e., façades, urban furniture) and structural typologies (i.e., short‐span footbridges, columns, floor systems) for which complex geometries derived from particular aesthetical criteria and/or construction time constrictions are governing parameters. Additionally, some authors claim that this process allows improving the sustainability of structures, as less material is necessary compared to traditional concrete solutions, thus reducing greenhouse gas emissions linked to material consumption. Nonetheless, the environmental implications of DFC are still under scrutiny and remain objectively unquantified. In this study, a sustainability assessment model to allow decision‐makers to evaluate and compare concrete footbridge alternatives—from the sustainability perspective—including those constructed by means of 3D printed concrete (3DPC) techniques, is presented. The proposed approach is based on the MIVES method. For this purpose, the most representative criteria and indicators of sustainability identified are measured and weighted‐aggregated in a decision‐making tree. The sustainability index (SI) of each alternative is the outcome derived from the application of the model, and the SI was used as reference for evaluating the alternatives. The sustainability of 3D‐printed footbridges is quantified and compared to other concrete‐based solutions: traditional reinforced cast‐in‐place and precast concrete, as traditional solutions, and ultra‐high performance precast concrete and textile‐reinforced concrete, as innovative alternatives. The results of the analysis lead to conclude that 3D‐printed footbridges have positive impacts on environmental and social indicators, but economic indicators still need to be improved to attain a competitive solution. The approach proposed herein to assess the sustainability of footbridges can be extended to other cases and stakeholders' preferences by adapting the components of the method to sensitivities and particular boundary conditions of other scenarios.
With increasing construction activity and concrete consumption globally, the economic, environmental, and social impacts of human activities continue to increase rapidly. Therefore, it is imperative to assess the choice and construction of each structure and structural component from a sustainability-based perspective. In this study, such a multi-criteria decision-making approach using the MIVES method is applied to the choice of grouped continuous flight auger (CFA) piles. Different alternatives of CFA piles are studied: length (10 and 20 m), reinforcement (steel cage reinforcement and structural fibers), and aggregates (natural crushed aggregates and recycled aggregate concrete sourced from stationary and mobile recycling plants), based on experimentally verified mix designs. All alternatives were analyzed considering economic, environmental, and social requirements, using a decision-making tree with eight criteria and eleven indicators, with weights assigned by an expert panel. The results of the analysis showed a clear advantage in terms of all three sustainability requirements for CFA piles with steel fibers and recycled aggregate concrete, with all solutions with steel cage reinforcement having significantly lower values of the sustainability index. Such results demonstrate the need for implementing innovative solutions even in structural members such as CFA piles that are often considered in insufficient detail.