Investigating the effect of copper slag and halloysite on the durability of self-sensing alkali-activated slag mortar using the Taguchi method

Document Type : Research Paper

Authors

1 Faculty of Civil Engineering, Shahid Rajaee Teacher Training Unversity,, Tehran, Iran

2 Faculty of Civil Enfgineering, Shahid Rajaee Teacher Training University, Tehran, Iran

3 Faculty of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran

10.22124/jcr.2025.29716.1692

Abstract

Abstract:

Alkali-activated slag-based materials are a type of stable and environmentally compatible substance that, due to their alkaline nature, inherently exhibit higher electrical conductivity than Portland cement. Given their favorable sensory and mechanical properties, they can be utilized for structural health monitoring and measuring the physical parameters of structures under diverse environmental conditions. Structures in destructive/aggressive environments such as seawater, dams, bridge foundations, water supply tunnels, and other hydraulic infrastructures are exposed to risks due to chloride ions, microorganisms, and sulfate attacks. Therefore, investigating the durability of self-sensing alkali-activated slag-based mortar in such aggressive environments is essential. This study employs the Taguchi method to evaluate the effects of various parameters on the compressive strength and conductivity of geopolymer mortar containing conductive fillers like halloysite and copper slag, immersed in a sulfate-rich environment. The conducted analyses and tests include XRF, XRD, compressive strength, conductivity measurements, and SEM studies. Results revealed that the mix design of T3-C5-H15-M12-A55 showed the highest conductivity in the sulfate environment, and increasing sodium hydroxide molarity positively influenced the geopolymer mortar’s conductivity. Additionally, substituting steel slag with conductive fillers demonstrated superior performance, with higher-quality crystallization development. Increased steel slag and filler content proportionally elevated calcium levels, promoting the formation of C-A-S-H and C-S-H gels, which reduced porosity and enhanced microstructural integrity.

Keywords

Main Subjects

References

[1] M. Taylor, C. Tam, and D. Gielen, "Energy efficiency and CO2 emissions from the global cement industry," Korea, vol. 50, no. 2.2, p. 61.7, 2006.
[2] V. Malhotra, "Introduction: sustainable development and concrete technology," Concrete International, vol. 24, no. 7, 2002.
[3] P.-W. Chen and D. D. L. Chung, "Carbon fiber reinforced concrete for smart structures capable of non-destructive flaw detection," Smart Materials and Structures, vol. 2, no. 1, pp. 22-30, 1993/03/01 1993, doi: 10.1088/0964-1726/2.
[4] K. J. D. MacKenzie and M. J. Bolton, "Electrical and mechanical properties of aluminosilicate inorganic polymer composites with carbon nanotubes," Journal of Materials Science, vol. 44, no. 11, pp. 2851-2857, 2009/06/01 2009.
[5] S. Sun et al., "Multi-layer graphene-engineered cementitious composites with multifunctionality/intelligence," Composites Part B: Engineering, vol. 129, pp. 221-232, 2017/11/15/ 2017, doi: https://doi.org/10.1016/j.compositesb.2017.07.063
[6] B. G. Han, B. Z. Han, and X. Yu, "Effects of the content level and particle size of nickel powder on the piezoresistivity of cement-based composites/sensors," Smart Materials and Structures, vol. 19, no. 6, p. 065012, 2010/04/30 2010, doi: 10.1088/0964-1726/19/6/065012.
[7] B. Han, S. Ding, and X. Yu, "Intrinsic self-sensing concrete and structures: A review," Measurement, vol. 59, pp. 110-128, 2015/01/01/ 2015, doi: https://doi.org/10.1016/j.measurement.2014.09.048[8] B. Han, X. Yu, and J. Ou, Self-sensing concrete in smart structures. Butterworth-Heinemann, 2014.
[9] J. Davidovits, "Geopolymers: inorganic polymeric new materials," Journal of Thermal Analysis and calorimetry, vol. 37, no. 8, pp. 1633-1656, 1991.
[10] H. F. Taylor, Cement chemistry. Thomas Telford London, 1997.
[11] X. Feng, E. J. Garboczi, D. P. Bentz, P. E. Stutzman, and T. O. Mason, "Estimation of the degree of hydration of blended cement pastes by a scanning electron microscope point-counting procedure," Cement and Concrete Research, vol. 34, no. 10, pp. 1787-1793, 2004/10/01/ 2004, doi: https://doi.org/10.1016/j.cemconres.2004.01.014.
[12] L. N. Assi, E. Deaver, M. K. ElBatanouny, and P. Ziehl, "Investigation of early compressive strength of fly ash-based geopolymer concrete," Construction and Building Materials, vol. 112, pp. 807-815, 2016/06/01/ 2016, doi: https://doi.org/10.1016/j.conbuildmat.2016.03.008.
[13] J. L. Provis et al., "RILEM TC 247-DTA round robin test: mix design and reproducibility of compressive strength of alkali-activated concretes," Materials and Structures, vol. 52, no. 5, p. 99, 2019/09/10 2019, doi: 10.1617/s11527-019-1396-z.
[14] M. N. N. Khan and P. K. Sarker, "Effect of waste glass fine aggregate on the strength, durability and high temperature resistance of alkali-activated fly ash and GGBFS blended mortar," Construction and Building Materials, vol. 263, p. 120177, 2020/12/10/ 2020, doi: https://doi.org/10.1016/j.conbuildmat.2020.120177[15] A. M. Aguirre-Guerrero, R. A. Robayo-Salazar, and R. Mejía de Gutiérrez, "Corrosion resistance of alkali-activated binary reinforced concrete based on natural volcanic pozzolan exposed to chlorides," Journal of Building Engineering, vol. 33, p. 101593, 2021/01/01/ 2021, doi: https://doi.org/10.1016/j.jobe.2020.101593.
[16] L.-l. Kan, J.-w. Lv, B.-b. Duan, and M. Wu, "Self-healing of Engineered Geopolymer Composites prepared by fly ash and metakaolin," Cement and Concrete Research, vol. 125, p. 105895, 2019/11/01/ 2019, doi: https://doi.org/10.1016/j.cemconres.2019.105895.
[17] G. F. Huseien and K. W. Shah, "Durability and life cycle evaluation of self-compacting concrete containing fly ash as GBFS replacement with alkali activation," Construction and Building Materials, vol. 235, p. 117458, 2020/02/28/ 2020, doi: https://doi.org/10.1016/j.conbuildmat.2019.117458[18] J. He, G. Zhang, S. Hou, and C. Cai, "Geopolymer-based smart adhesives for infrastructure health monitoring: concept and feasibility," Journal of Materials in Civil Engineering, vol. 23, no. 2, pp. 100-109, 2011.
[19] M. Suweni Muntini and H. Ahmadi, "Performance of metakaolin geopolymer ceramic for fiber optic temperature sensor," Materials Today: Proceedings, vol. 5, no. 7, Part 1, pp. 15137-15142, 2018/01/01/ 2018, doi: https://doi.org/10.1016/j.matpr.2018.04.071.
 

Files

Share

How to cite

Statistics