Multiple Dimensions of Energy Efficiency of Recycled Concrete: A Systematic Review.

The focus on building energy efficiency using alternative materials in structures, especially concrete, and the main technical and environmental challenges therein, aligns with Sustainable Development Goals (SDG). This study proposes a review that analyzes structures made with recycled concrete, relating to the energy efficiency of buildings. A classification structure was proposed, addressing the following questions: (i) What are the various dimensions in which research into energy-efficient recycled concrete is concentrated? (ii) What are the themes and classes of research associated with these dimensions? (iii) What are the main shortcomings of current approaches, and what would be a good research agenda for the future development of energy-efficient recycled concrete? A bibliometric analysis was carried out, presenting geographical and cluster maps to understand different research trends and refine future research. This was followed by a bibliographic analysis, reviewing the most relevant studies from the last five years (2019–2024). The results showed some residual alternative materials (around 45 types from five different industries) used in the production of energy-efficient concrete. And, as a negative effect, as substitution rates increase, porosity is the property with the greatest impact on energy efficiency. The greater the number of pores and the greater their interconnection, the lower the material's thermal insulation. [ABSTRACT FROM AUTHOR]