Strength Behavior and Microstructure Characterization of Self-Consolidating Concrete with Sintered Fly Ash Coarse Aggregates

Abstract

Self-consolidating concrete (SCC) made with sintered fly ash aggregates (SFAA) was investigated for its compressive strength and microstructural properties. Even with significant additions of mineral admixtures such as silica fume (SF) and metakaolin (MK) and 100% SFAA, the formulated SCC demonstrated compressive strength satisfying the minimum requirements for structural lightweight concrete, in accordance with established standards such as those recommended by the ACI 318-19, BS EN 206-1 and Eurocode 2 after 28 and 90 days of curing. Strength development was corroborated through SEM and EDS analysis, while non-destructive methods, including rebound hammer and ultrasonic pulse velocity (UPV), confirmed the enhancements in compressive strength.

Keywords

• Sintered fly ash aggregates
• self-consolidating concrete
• mineral admixtures
• microstructural investigation

References

1. Ankur, N., & Singh, N. (2024a). Strength characterization and sustainability assessment of coal bottom ash concrete. In Environmental Science and Pollution Research (Number 0123456789). Springer Berlin Heidelberg. https://doi.org/10.1007/s11356-024-33303-z
2. Ankur, N., & Singh, N. (2024b). Valorisation of bottom ash in concrete: serviceability, microstructural and sustainability characterisation. Magazine of Concrete Research, 76(21), 1241–1265. https://doi.org/10.1680/jmacr.23.00313
3. Ankur, N., & Singh, N. (2026a). Coal Bottom Ash Concrete under Extreme Exposure Conditions: A Sustainable Solution for Environmental Protection. Journal of Materials Engineering and Performance. https://doi.org/10.1007/s11665-026-14085-6
4. Ankur, N., & Singh, N. (2026b). Permeation, Toxicity, and Sustainability Assessment of Thermal Coal-Residue Concrete. Journal of Materials in Civil Engineering, 38(2). https://doi.org/10.1061/JMCEE7.MTENG-21661
5. Gökçe, H. S., Hatungimana, D., & Ramyar, K. (2019). Effect of fly ash and silica fume on hardened properties of foam concrete. Construction and Building Materials, 194, 1–11. https://doi.org/10.1016/j.conbuildmat.2018.11.036
6. Güneyisi, E., Gesoǧlu, M., Karaoǧlu, S., & Mermerdaş, K. (2012). Strength, permeability and shrinkage cracking of silica fume and metakaolin concretes. Construction and Building Materials, 34, 120–130. https://doi.org/10.1016/j.conbuildmat.2012.02.017
7. IS 516 Part 1/Sec 1. (2021). Hardened Concrete — Methods of Test Part 1 Testing of Strength of Hardened Concrete. BUREAU OF INDIAN STANDARDS.
8. Kumar, P., Dinakar, P., & Saravanan, T. J. (2024a). Development and Mechanical Performance of Self-Compacting Lightweight Aggregate Concrete Using Sintered Fly Ash Aggregates. 36(7). https://doi.org/10.1061/JMCEE7.MTENG-17831

9. Kumar, P., Dinakar, P., & Saravanan, T. J. (2024b). Development and Mechanical Performance of Self-Compacting Lightweight Aggregate Concrete Using Sintered Fly Ash Aggregates. 36(7). https://doi.org/10.1061/JMCEE7.MTENG-17831
10. Kumar, P., Dinakar, P., & Saravanan, T. J. (2025). Development and performance analysis of structural lightweight aggregate self-compacting concrete: A sustainable solution. Process Safety and Environmental Protection, 197(February), 107052. https://doi.org/10.1016/j.psep.2025.107052
11. Kumar, P., Pasla, D., & Saravanan, T. J. (2023a). Self-compacting lightweight aggregate concrete and its properties : A review. Construction and Building Materials, 375(February), 130861. https://doi.org/10.1016/j.conbuildmat.2023.130861
12. Kumar, P., Pasla, D., & Saravanan, T. J. (2023b). Self-compacting lightweight aggregate concrete and its properties : A review. Construction and Building Materials, 375(February), 130861. https://doi.org/10.1016/j.conbuildmat.2023.130861
13. Kumar, P., Pasla, D., & Thiyagarajan, J. S. (2025). Synergetic effect of coarse sintered fly ash aggregates and supplementary cementitious materials in self-compacting concrete: From durability and corrosion perspective. Journal of Building Engineering, 108(January), 112969. https://doi.org/10.1016/j.jobe.2025.112969
14. Kumar, P., & Singh, N. (2023). Performance of recycled concrete aggregates based self-compacting concrete containing coal combustion ashes and silica fume. European Journal of Environmental and Civil Engineering, 0(0), 1–26. https://doi.org/10.1080/19648189.2023.2293816
15. Mermerdaş, K., Gesoǧlu, M., Güneyisi, E., & Özturan, T. (2012). Strength development of concretes incorporated with metakaolin and different types of calcined kaolins. Construction and Building Materials, 37, 766–774. https://doi.org/10.1016/j.conbuildmat.2012.07.077
16. Nadesan, M. S., & Dinakar, P. (2017). Structural concrete using sintered flyash lightweight aggregate: A review. Construction and Building Materials, 154, 928–944. https://doi.org/10.1016/j.conbuildmat.2017.08.005
17. Nadesan, M. S., & Pasala, D. (2018). Materials and methods of sintered flyash lightweight aggregate. Indian Journal of Scientific Research, 17(2), 24–31.
18. Naito, C., Fox, J., Bocchini, P., & Khazaali, M. (2020). Chloride migration characteristics and reliability of reinforced concrete highway structures in Pennsylvania. Construction and Building Materials, 231, 117045. https://doi.org/10.1016/j.conbuildmat.2019.117045
19. Rawat, R., & Pasla, D. (2024). Mix design of FA-GGBS based lightweight geopolymer concrete incorporating sintered fly ash aggregate as coarse aggregate. Journal of Sustainable Cement-Based Materials, 13 (8), 1164–1179. https://doi.org/10.1080/21650373.2024.2361266
20. Tejas, S., & Pasla, D. (2023a). Assessment of mechanical and durability properties of composite cement-based recycled aggregate concrete. Construction and Building Materials, 387 (February 2023), 131620. https://doi.org/10.1016/j.conbuildmat.2023.131620
21. Tejas, S., & Pasla, D. (2023b). Assessment of mechanical and durability properties of composite cement-based recycled aggregate concrete. Construction and Building Materials, 387 (May 2023), 131620. https://doi.org/10.1016/j.conbuildmat.2023.131620