Comparative Study of Metakaolin-Quicklime and Metakaolin-Bacillus Subtilis as Self-Healing Agents in Concrete

Year 2024, Volume: 21 Issue: 1, 42 - 53, 01.05.2024

Ganiu Adeagbo , Grace Modupeola Amusan

Abstract

The study examined the physical, mechanical, and crack-healing properties of concrete produced using Metakaolin-Bacillus subtilis and Metakaolin-Quicklime as self-healing agents. Two concrete specimens of grade M30 were produced; the first specimens were prepared incorporating metakaolin and quicklime of replacement percentages of 5, 10, and 15 by weight of cement, respectively, and the second, incorporating metakaolin of the same replacement percentages and 10 ml Bacillus subtilis. The mechanical properties were conducted at 28 days on concrete cubes of size 150 × 150 × 150 (mm3) and concrete beams of size 400 × 100 × 100 (mm3). The self-healing efficiency was evaluated through crack induction, and subsequent analyses included a comparative examination of the crack closure mechanisms for each agent. The compressive strength at 28 days’ curing age showed that 10% replacement of metakaolin-bacillus subtilis yields the best strength of 41.2 MPa, a 17.8% increase over the control specimen. Also, the combined blend of metakaolin and quicklime showed the highest strength at 10% replacement, which gained a 53% increase over the control specimen. The comparative analysis between metakaolin-quicklime and metakaolin-Bacillus subtilis reveals that both combinations exhibit self-healing properties through different mechanisms. In conclusion, the study establishes the efficacy of metakaolin, quicklime, and Bacillus subtilis as promising selfhealing agents in concrete, showcasing their unique mechanisms and paving the way for enhanced durability and structural integrity in construction applications.

Keywords

Self-healing agents, Compressive strength, Flexural strength, Crack healing

References

• M. Azam, N. Ghabbour, S. Ahmed, and A. Hosny, “Evaluation of metakaolin’s pozzolanic activity and its impact on microstructure of self-healing concrete.” Construction and Building Materials, vol. 207, pp. 93-104, 2019.
• S. V. Kulkarni, and P. G Koppad, “Self-Healing Concrete: A Comprehensive Review.” Construction and Building Materials, vol. 176, pp. 478-495, 2018.
• X. Luo, N. Han, T. Ngo, and P. A. Mendis, “Review on the Use of Metakaolin in Cement-Based Materials.” Construction and Building Materials, vol. 124, pp. 676-690, 2016.
• H. M. Jonkers, “Bacteria-based self-healing concrete.” Heron., vol. 56, no. ½, pp. 1-12, 2011.
• K. V. Tittelboom, and D. B. Nele, “Self-healing in cementitious materials-a review.” Materials, vol. 6, no. 6, pp. 2182-2217, 2013.
• M. Santhanam, M. D. Cohen, and J. Olek, “Microstructure, and properties of metakaolin concrete: A state-of-the-art review.” Cement and Concrete Composites, vol. 33, no. 2, pp. 110-121, 2011.
• B. W. Jo, and G. H. Kim, “A review on the role of metakaolin in concrete.” Construction and Building Materials, vol. 209, pp. 233-242, 2019.
• Z. Li, J. Zhou, Y. Wang, and T. Ji, “Metakaolin-induced crystalline healing of concrete cracks.” Cement and Concrete Composites, vol. 101, pp. 221-231, 2019.
• B. Han, W. Sun, and X. Zhang, “Impact of metakaolin on autogenous healing of concrete.” Construction and Building Materials, vol. 179, pp. 68-75, 2018.
• H. Kalhori, and R. Bagherpour, “Application of carbonate precipitating bacteria for improving properties and repairing of cracks of shortcrete.” Construction and Building Materials, vol. 148, pp. 249-260, 2017.
• N. H. Balam, D. Mostofinejad, and M. Eftekhar, “Effects of bacterial remediation on compressive strength, water absorption, and chloride permeability of lightweight aggregate concrete.” Construction and Building Materials, vol. 145, pp. 107-116, 2017.
• S. Farhadi, and S. Ziadloo, “Self-healing microbial concrete - A review.” Materials Science Forum, vol. 990, pp. 8-12, 2019.
• Y. Jiang, Z. Lv, J. Hu, and C. Yan, “Synergistic effect of metakaolin and Bacillus subtilis on autogenous healing of concrete.” Construction and Building Materials, vol. 173, pp. 117-126, 2018.
• N. Yamasamit, P. Sangkeaw, W. Jitchaijaroen, C. Thongchom, S. Keawsawasvong, and V. Kamchoom, “Effect of Bacillus subtilis on mechanical and self-healing properties in mortar with different crack widths and curing conditions.” Scientific Reports, vol. 13, no. 1, pp. 7844, 2023.
• A. Gharzouni, K. Van Tittelboom, N. De Belie, and W. De Muynck, “Combined effects of metakaolin and Bacillus subtilis on concrete's mechanical properties and biological healing.” Construction and Building Materials, vol. 277, pp. 122217, 2021.
• J. S. Lee, H. K. Kim, and J. K. Song, “Combined effects of metakaolin and Bacillus subtilis on the mechanical and durability properties of self-healing concrete.” Construction and Building Materials, vol. 262, pp.120530, 2022.
• G. Dall'Igna, A. Enfedaque, G. Mazzotta, L. Binda, and C. Sbarufatti, "Crack width reduction in self-healing concrete with metakaolin and Bacillus subtilis.” Cement and Concrete Composites, vol. 115, pp. 103740, 2020.
• L. Coppola, H. Di Benedetto, L. Torre, R. Cioffi, and F. Fava, “Long-term environmental durability of self-healing concrete with metakaolin and Bacillus subtilis.” Construction and Building Materials, vol. 293, pp. 123409, 2021.
• BS 1881, “Method for Determination of Slump” Part 102:1-10, British Standard Institution, London, 1983.
• BS 882, “Specification for Aggregates from Natural Sources for Concrete” British Standard Institution, London, 1992.
• BS 1881, “Method for Determination of Compacting Factor.” Part 103:1-12, British Standard Institution, London, 1993.
• BS 1881, “Method for Determination of the Compressive Strength of Concrete Cores.” Part 116, pp. 1-9, British Standard Institution, London, 1983.
• BS 1881, “Method for Determination of Flexural Strength.” Part 118, pp. 1-12, British Standard Institution, London, 1983.
• International Organization for Standardization, “Water quality determination of selected phthalates using GC-MS and GC-MS/MS.” ISO 18477, ISO, 2015.
• American Standard for Testing and Materials, “Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for use in Concrete.” ASTM C618-94;2013; ICS 91.100. 30. American Standard for Testing and Materials, 1994.