The increasing interest in recycled aggregates as an alternative to natural resources has generated a rapidly expanding body of scientific literature; however, the global evolution, intellectual structure, and emerging research directions of this field require comprehensive assessment. This study ana-lyzes two decades of research on recycled aggregates in concrete through a bibliometric and sci-ence-mapping approach. Bibliographic records indexed in Scopus between 2006 and 2025 were retrieved using the search terms “recycled aggregate” and “concrete” and analyzed using Biblio-metrix/Biblioshiny and VOSviewer. A total of 14,044 documents from 1,513 sources were identified, showing an annual growth rate of 19.51%, with publications increasing from 74 in 2006 to 2,189 in 2025. China emerged as the leading country in scientific production, while Tongji University was the most productive institution. Keyword co-occurrence analysis revealed three major conceptual domains associated with recycled aggregate utilization, mechanical performance and durability, and sustainability and environmental impact. Thematic evolution showed a progressive transition from research focused primarily on compressive strength and technical feasibility toward more integrated approaches involving durability, microstructure, sustainable development, and waste utilization. Recent topics such as machine learning, forecasting, carbon sequestration, and geo-polymer concrete indicate an emerging shift toward predictive tools and decarbonization-oriented strategies. Overall, the findings demonstrate that recycled aggregate concrete research has evolved from establishing technical feasibility toward optimizing material performance, environmental benefits, and advanced predictive assessment.

This study analyzes the mechanical behavior of sustainable concrete when incorporating recycled polyethylene terephthalate [PET] as a partial replacement for fine aggregate. Articles reporting mixtures with 5% and 10% replacements were reviewed. A total of thirteen mixtures and thyrty-five 28-day compressive strength data points were collected and compared with control mixtures. The statistical analysis included measures of central tendency, dispersion, and percentage variation, wich allowed for the normalization of result between different studies. The findings show that the 5% replacement has an average variation of -2.6%, indicating a minimal impact on strength, while the 10% replacement reports an average reduction of -11.9%. Although variability was observed, fine-grained PET favored compactness and mechanical performance. These results consolidate 5% as a viable technical alternative, with enviromental and circular economy benefits.