Effect of alkaline activator on static and dynamic properties of geopolymer mortars containing ferrock and fibers

Document Type : Original Article

Authors

Amir Hosein Varasteh ¹

Seyed Hosein Ghasemzadeh Mousavinejad ²

¹ civil engineering master student at university of Guilan

² Civil Engineering, Engineering Faculty member, university of Guilan

10.22067/jfcei.2025.88923.1312

Abstract

Cement is one of the most widely used construction materials in the world. Its production process is highly polluting and leads to the release of carbon dioxide (CO₂) into the atmosphere. In addition to CO₂ emissions, cement production generates millions of tons of kiln dust annually, causing respiratory health risks and environmental pollution. Ferrock, an innovative iron-based compound, is a carbon-free alternative to cement that utilizes industrial waste for a versatile construction material. Accordingly, this study investigated the effect of alkaline activators on the static and dynamic properties of geopolymer mortars containing ferrock and polypropylene fibers. The variables in this study included two liquid-to-binder ratios (0.4 and 0.5), two sodium silicate-to-sodium hydroxide ratios (1.5 and 2), various replacement percentages of ferrock (5%, 8%, 12%, and 15%), and polypropylene fibers (0.1%, 0.2%, 0.3%, and 0.5%) across three steps. The results showed that curing in ambient conditions performed better than water curing. Samples containing 8% ferrock and 0.1% fibers exhibited the best performance. The compressive strength of the samples after 28 days reached 75.2 MPa, and the flexural strength was recorded at 5.52 MPa. Furthermore, in the electrical resistivity test, a maximum value of 144.6 kΩ•cm was observed. The inclusion of fibers, even in small amounts, significantly improved impact resistance, with a maximum increase of 57% being observed. These findings demonstrate that the use of ferrock and polypropylene fibers is an effective strategy for enhancing the mechanical and environmental properties of construction mortars.

Keywords

alkaline activator

ferrock

green cement

geopolymer

fibers

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References

1. Vickers, A. Van Riessen, and W. D. Rickard, Fire-resistant geopolymers: role of fibres and fillers to enhance thermal properties. Singapore: Springer, 2015.
2. S. Vijayan, S. Arvindan, and T. S. Janarthanan, "Evaluation of ferrock: A greener substitute to cement," Materials Today: Proceedings, vol. 22, pp. 781–787, 2020. https://doi.org/10.1016/j.matpr.2019.10.147
3. Jose and R. Vasudev, "Ferrock: Carbon negative substitute for cement—A review," Sustainability, Agri, Food and Environmental Research, 2023. https://doi.org/10.7770/safer-V12N-art784
4. A. V. I. T. A. Singh, "Compressive strength study of green concrete by using ferrock," Multidisciplinary International Research Journal, Gujarat Technological University, vol. 2, pp. 63–80, 2020.
5. L. Garcia, A. T. Achaiah, J. Bello, and T. Donovan, "Ferrock: A life cycle comparison to ordinary Portland cement," Industrial Ecology, Denver, CO, USA, 2017.
6. R. Latifi, Ö. Biricik, and A. M. Aghabaglou, “Effect of the addition of polypropylene fiber on concrete properties,” Journal of Adhesion Science and Technology, vol. 36, no. 4, pp. 345–369, 2022. https://doi.org/10.1080/01694243.2021.1922221
7. H. G. Mousavinejad, A. Darvishalinezhad, and M. S. BazKiagourabi, “Effect of polypropylene fibers versus macrobarchip on the characteristics of plastic concrete,” Ferdowsi Civil Engineering Journal, vol. 37, no. 2, pp. 99–122, 2024. https://doi.org/10.22067/jfcei.2024.80952.1215
8. C. Madhavi, L. S. Raju, and D. Mathur, “Polypropylene fiber reinforced concrete-a review,” International journal of emerging technology and advanced engineering, vol. 4, no. 4, pp. 114–118, 2014.
9. Liu, L. Wang, K. Cao, and L. Sun, “Review on the durability of polypropylene fibre-reinforced concrete,” Advances in Civil Engineering, vol. 2021, pp. 1–13, 2021. https://doi.org/10.1155/2021/6652077
10. Elkatatny, R. Gajbhiye, A. Ahmed, and A. A. Mahmoud, “Enhancing the cement quality using polypropylene fiber,” Journal of Petroleum Exploration and Production Technology, vol. 10, pp. 1097–1107, 2020. https://doi.org/10.1007/s13202-019-00804-4
11. R. Mehr and H. Bakhshi, “Effect of steel fibers and concrete strength on mechanical specifications of steel fiber reinforced concrete,” Concrete Research, vol. 8, no. 1, pp. 101–112, 2015.
12. ASTM C778, Standard Specification for Standard Sand, ASTM International, 2021. [Online]. Available: https://doi.org/10.1520/C0778-21.
13. ASTM C109, Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or [50-mm] Cube Specimens), ASTM International, 2020. [Online]. Available: https://doi.org/10.1520/c0109_c0109m-20.
14. ASTM C348-08, Test Method for Flexural Strength of Hydraulic-Cement Mortars, ASTM International, 2014. [Online]. Available: https://doi.org/10.1520/c0348-08.
15. ASTM C1202-10, Standard test method for electrical indication of concrete’s ability to resist chloride ion penetration, ASTM International, 2012. [Online]. Available: https://doi.org/10.1520/C1202-10.
16. ASTM C597-22, Test Method for Pulse Velocity Through Concrete, ASTM International, 2023. [Online]. Available: https://doi.org/10.1520/c0597-22.
17. M. Rahman, M. Usman, and A. A. Al-Ghalib, "Fundamental properties of rubber modified self-compacting concrete (RMSCC)," Construction and Building Materials, vol. 36, pp. 630–637, 2012. https://doi.org/10.1016/j.conbuildmat.2012.04.116
18. ACI Committee 544.2R, Measurement of Properties of Fiber Reinforced Concrete, Detroit, MI, USA: American Concrete Institute, 1989.
19. ASTM C948, Standard test method for dry and wet bulk density, water absorption, and apparent porosity of thin sections of Glass-Fiber reinforced concrete, ASTM International, 2023. [Online]. Available: https://doi.org/10.1520/C0948-81R23.
20. Shivani, N. Nihana, A. Gowri, H. Jalal, R. Arjun, and M. Jinudarsh, "Experimental investigation of ferrock by complete and partial replacement of cement in concrete," International Research Journal of Engineering and Technology, vol. 9, pp. 855–862, 2022.
21. AASHTO-TP-95-14, Standard Method of Test for Surface Resistivity Indication of Concrete's Ability to Resist Chloride Ion Penetration, American Association of State and Highway Transportation Officials, 2014.
22. A. Whitehurst, "Soniscope tests concrete structures," Journal Proceedings, vol. 47, no. 2, pp. 433–444, 1951.
23. L. Wilson and P. D. Tennis, Design and control of concrete mixtures. Portland, OR, USA: Portland Cement Association, 2021.
24.  
25.