Abstract
This study evaluates the mechanical and durability performance of sustainable two-stage concrete incorporating recycled fine and coarse aggregates obtained from building demolition waste. Four two-stage concrete mixtures were produced: NN with natural coarse and fine aggregates, RR with recycled coarse and fine aggregates, NM with natural coarse aggregate and mixed fine aggregate, and RM with recycled coarse aggregate and mixed fine aggregate. The mixed fine aggregate consisted of 50% natural sand and 50% recycled sand by mass. A conventional concrete mixture was also prepared as an additional reference. The experimental program included grout flexural and compressive strength, concrete compressive strength, ultrasonic pulse velocity, X-ray-based pore structure assessment, and water penetration under pressure. The results showed that recycled fine aggregate can be used effectively in grout production under the investigated conditions. The recycled sand grout reached a 90-day compressive strength of 49.25 MPa, slightly higher than the natural sand grout, although its flexural-strength response was lower and more variable. The fully recycled RR mixture achieved a 28-day compressive strength of 39.40 MPa, corresponding to 94.8% of the natural aggregate reference mixture. X-ray analysis showed that RR had a relatively low total air content of 0.82%, which supported its mechanical performance. RR also showed the lowest mean water penetration depth, 50.7 mm; however, this result was highly variable and should be interpreted as a mixture-specific observation governed by grout filling, aggregate packing, pore connectivity, and interface continuity rather than as a general improvement caused by recycled aggregates. Overall, the findings indicate that demolition-waste-derived recycled aggregates can be incorporated into two-stage concrete when aggregate quality, grading, grout rheology, and curing conditions are carefully controlled. Similar content being viewed by others Impact of using recycled plastic particles as a partial replacement of aggregates on the mechanical performance of the eco-friendly concrete Article Open access 16 June 2026 Assessing the environmental impacts of upcycling recycled aggregates into concrete with consideration of resource flows and substitution effects Article Open access 27 November 2025 Compressive strength prediction of carbonated recycled aggregate concrete using regression based machine learning models Article Open access 20 January 2026 Acknowledgements The authors acknowledge the support of the Faculty of Civil and Environmental Engineering, Gdańsk University of Technology. Funding This research received no external funding. Author information Authors and Affiliations Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Gdańsk, Poland Farzam Omidi Moaf, Marzena Kurpińska, Hakim S. Abdelgader, Mikołaj Miśkiewicz & Łukasz Skarżyński Civil Engineering Department, Faculty of Engineering, University of Tripoli, Tripoli, Libya Hakim S. Abdelgader Corresponding author Correspondence to Farzam Omidi Moaf. Ethics declarations Competing interests The authors declare no competing interests. Additional information Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. 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Verify currency and authenticity via CrossMark Cite this article Moaf, F.O., Kurpińska, M., Abdelgader, H.S. et al. Mechanical performance and water penetration resistance of two-stage concrete incorporating recycled aggregates from demolition waste. Sci Rep (2026). https://doi.org/10.1038/s41598-026-63298-1 Download citation Received 03 June 2026 Accepted 17 July 2026 Published 22 July 2026 DOI https://doi.org/10.1038/s41598-026-63298-1 Share this article Anyone you share the following link with will be able to read this content: Get shareable link Provided by the Springer Nature SharedIt content-sharing initiative Keywords Two-stage concrete Preplaced aggregate concrete Recycled aggregates Demolition waste Sustainable concrete Mechanical performance Durability Subjects Engineering Environmental sciences Materials science Scientific Reports (Sci Rep) ISSN 2045-2322 (online) nature.com footer links About Nature Portfolio About us Press releases Press office Contact us Discover content Journals A-Z Articles by subject protocols.io Nature Index Publishing policies Nature portfolio policies Open access Author & Researcher services Reprints & permissions Research data Language editing Scientific editing Nature Masterclasses Research Solutions Libraries & institutions Librarian service & tools Librarian portal Open research Recommend to library Advertising & partnerships Advertising Partnerships & Services Media kits Branded content Professional development Nature Awards Nature Careers Nature Conferences Regional websites Nature Africa Nature China Nature India Nature Japan Nature Middle East Privacy Policy Use of cookies Your privacy choices/Manage cookies Legal notice Accessibility statement Terms & Conditions Your US state privacy rights Springer Nature © 2026 Springer Nature Limited Close Get the most important science stories of th