Sulfate Attack and Microstructural Study of Self-Compacting Sand Concrete Incorporating Recycled Concrete

Authors

• S. Boudali, Team Leader – Materials Testing and Quality Control Nvira, Québec, Canada
• A.M. Soliman, Associate Professor, Department of Building, Civil and Environmental Engineering,Concordia University Montreal, Montréal, Canada
• B. Abdulsalam, Postdoctoral fellow, Department of Civil and Environment Engineering, Western University, London, Ontario, Canada
• S. Poncet, Professor, Department of Mechanical Engineering, Université de Sherbrooke, Québec, Canada
• Adel ElSafty, Distinguished Professor, University of North Florida, Jacksonville, Florida, USAFollow

Abstract

This study presents an experimental investigation of the microstructure of Self-Compacting Sand Concrete (SCSC) containing recycled concrete aggregates (RCA) and fine recycled concrete powder (FRCP) under a sulfate attack. SCSC specimens were submerged and stored for one year in a sodium sulfate solution. The microstructure of SCSC was investigated using quantitative X-ray diffraction and SEM analysis performed on samples taken from both the core and surface of the specimens. Also, the impact of different percentages and sizes of recycled aggregates (i.e., varying from nano- up to micro-sized aggregates) on the microstructural properties of SCSC exposed to sulfate attack was evaluated. It was noticed that the performance of SCSC concrete is affected by the type, nature, and size of RCA within the mixture. This study confirmed that the interfacial transition zone (ITZ) properties and the replacement level of recycled aggregates, including recycled fine aggregates, have a significant effect on durability. The results indicated that the microstructure of concrete mixtures improved with the incorporation of nano-fine recycled aggregates. It was also concluded that combining recycled fine aggregates and recycled concrete aggregates will lead to better performance under severe sulfate environments.

Keywords

Fine recycled concrete powder, Self-compacting sand concrete, Sulfate attack, Recycled concrete aggregates

Recommended Citation

Boudali, S.; Soliman, A.M.; Abdulsalam, B.; Poncet, S.; and ElSafty, Adel (2026) "Sulfate Attack and Microstructural Study of Self-Compacting Sand Concrete Incorporating Recycled Concrete," HBRC Journal: Vol. 22: Iss. 1, Article 39.
DOI: https://doi.org/10.65800/2090-9934.1038
Available at: https://journal.hbrc.edu.eg/journal/vol22/iss1/39