Title:
Improving Sulfate Resistance in Alkali-Activated Self-Compacted Concrete: Utilizing Precursor Combinations and Dry-Powder Activators as a Novel Approach for Enhanced Durability
Author(s):
Dima Kanaan
Publication:
Symposium Paper
Volume:
362
Issue:
Appears on pages(s):
127-146
Keywords:
alkali-activated SCC; durability; eco-concrete; silicate/carbonate; sulfate attack; ternary blend
DOI:
10.14359/51740879
Date:
6/5/2024
Abstract:
This study investigates the synthesis of alkali-activated self-compacted concrete (AASCC) mixtures, in which slag is replaced by fly ash (FA) and silica fume (SF), in various combinations including single, binary, and ternary precursors activated with a 1:1 ratio of sodium metasilicate and sodium carbonate. The impact of activator dosage and precursor combinations on the fresh and hardened properties as well as durability was evaluated. The AASCC combinations were subjected to rigorous sulfate attack scenarios and wetting-drying cycles. The efficient development of AASCC depends critically on the precise selection of precursor materials, proportions, activator type, and dosage, with larger fractions of sodium carbonate/silicate activators resulting in delayed reaction kinetics.
Slag replacement with various SF or FA class-F ratios modulated the particle size distribution of the total binder material, leading to enhancements in the characteristics of AASCC mixtures. The highest compressive strength and ultrasonic pulse velocity values were achieved at a 25% activator dosage. The emergence of diverse reaction products and binding gels, including C-(N)A-S-H, significantly influenced transport mechanisms such as capillary sorptivity, permeable pores, and bulk electrical resistivity. AASCC mixtures demonstrated resistance to sulfate attack for up to six months, indicating their potential for sustainable construction practices in sulfate-rich environments. This study provides valuable insights into the development of AASCC mixtures, paving the way for the wider use of sustainable construction materials.
Related References:
1. Whittaker, M., & Black, L., “Current knowledge of external sulfate attack”, Advances in Cement Research, V. 27, No. 9, 2015, pp. 532-545.
2. Kanaan, D., Soliman, A. M., & Safhi, A. E. M., “External Sulfate Attack of Ambient-Cured One-Part Alkali-Activated Self-Consolidating Concrete”, Sustainability, V. 15, No. 5, 2023, pp. 4127.
3. ASTM C1012, “Standard Test Method for Length Change of Hydraulic-Cement Mortars Exposed to a Sulfate Solution”, ASTM International, 2004, PA, USA.
4. Taylor, H. F., “Cement Chemistry”, V. 2, London: Thomas Telford, 1997.
5. Yu, C., Sun, W., & Scrivener, K., “Mechanism of expansion of mortars immersed in sodium sulfate solutions”, Cement and concrete research, V. 43, 2013, pp. 105-111.
6. Kunther, W., Lothenbach, B., & Scrivener, K. L., “On the relevance of volume increase for the length changes of mortar bars in sulfate solutions”, Cement and Concrete Research, V. 46, 2013, pp. 23-29.
7. Yang, J., Snoeck, D., De Belie, N., & Sun, Z., “Effect of superabsorbent polymers and expansive additives on the shrinkage of alkali-activated slag”, Cement and Concrete Composites, V. 123, 2021, pp. 104218.
8. Zhang, Z., Provis, J. L., Ma, X., Reid, A., & Wang, H., “Efflorescence and subflorescence induced microstructural and mechanical evolution in fly ash-based geopolymers”, Cement and Concrete Composites, V. 92, 2018, pp. 165-177.
9. Shi, Z., Shi, C., Wan, S., & Zhang, Z., “Effects of alkali dosage and silicate modulus on alkali-silica reaction in alkali-activated slag mortars”, Cement and Concrete Research, V. 111, 2018, pp. 104-115.
10. Bakharev, T., Sanjayan, J. G., & Cheng, Y. B., “Resistance of alkali-activated slag concrete to acid attack”, Cement and Concrete research, V. 33, No. 10, 2003, pp. 1607-1611.
11. Komljenović, M., Baščarević, Z., Marjanović, N., & Nikolić, V., “External sulfate attack on alkali-activated slag”, Construction and building materials, V. 49, 2013, pp. 31-39.
12. Zhu, H., Liang, G., Li, H., Wu, Q., Zhang, C., Yin, Z., & Hua, S., “Insights to the sulfate resistance and microstructures of alkali-activated metakaolin/slag pastes”, Applied Clay Science, V. 202, 2021, pp. 105968.
13. Li, Q., Li, X., Yang, K., Zhu, X., Gevaudan, J. P., Yang, C., & Basheer, M., “The longterm failure mechanisms of alkali-activated slag mortar exposed to wet-dry cycles of sodium sulphate”, Cement and Concrete Composites, V. 116, 2021, pp. 103893.
14. Liu, L., Xie, M., He, Y., Li, Y., Huang, X., Cui, X., & Shi, C., “Expansion behavior and microstructure change of alkali-activated slag grouting material in sulfate environment”, Construction and Building Materials, V. 260, 2020, pp. 119909.
15. Bonen, D., “Composition and appearance of magnesium silicate hydrate and its relation to deterioration of cement‐based materials”, Journal of the American Ceramic Society, V. 75, No. 10, 1992, pp. 2904-2906.
16. Bakharev, T., Sanjayan, J. G., & Cheng, Y. B., “Hydration of slag activated by alkalis”, The Australasian Ceramic Society, 1998, pp. 195-200.
17. Collins, F. G., “High early strength concrete using alkali activated slag”, Monash University, 1999.
18. Kanaan, D., Soliman, A. M., & Suleiman, A. R., “Zero-cement concrete resistance to external sulfate attack: a critical review and future needs”, Sustainability, V. 14, No. 4, 2022, pp. 2078.
19. Kanaan, D., Safhi, A. E. M., Suleiman, A. R., & Soliman, A. M., “Fresh, hardened, and microstructural properties of ambient cured one-part alkali-activated self-consolidating concrete”, Sustainability, V. 15, No. 3, 2023, pp. 2451.
20. EFNARC, “Specification and Guidelines for Self-Compacting Concrete”, European Federation of Producers and Applicators of Specialist Products for Structures, 2005, Norfolk, UK.
21. Malhotra, V. M., Carette, G., and Bremner, T., “Current Status of CANMET's Studies on the Durability of Concrete Containing Supplementary Cementing Materials in Marine Environment”, Special Publication, V. 109, 1988, pp. 31-72.
22. Wang, A., Freeman, J., and Jolliff, B., “Phase Transition Pathways of the Hydrates of Magnesium Sulfate in the Temperature Range 50 C to 5 C: Implication for Sulfates on Mars”, Journal of Geophysical Research: Planets, V. 114, No. E4, 2009.
23. Kamali, S., Moranville, M., and Leclerco, S., “Material and Environmental Parameter Effects on the Leaching of Cement Pastes: Experiments and Modelling”, Cement and Concrete Research, V. 38, 2008, pp. 575–585
24. Zuo, Y., Nedeljković, M., and Ye, G., “Coupled Thermodynamic Modelling and Experimental Study of Sodium Hydroxide Activated Slag”, Construction and Building Materials, V. 188, 2018, pp. 262-279.
25. Komljenović, M., Baščarević, Z., Marjanović, N., and Nikolić, V., “External Sulfate Attack on Alkali-Activated Slag”, Construction and Building Materials, V. 49, 2013, pp. 31-39.
26. Baščarević, Z., Komljenović, M., Miladinović, Z., Nikolić, V., Marjanović, N., and Petrović, R., “Impact of Sodium Sulfate Solution on Mechanical Properties and Structure of Fly Ash based Geopolymers”, Materials and Structures, V. 48, No. 3, 2015, pp. 683-697.
27. Sindhunata, Provis, J. L., Lukey, G. C., Xu, H., and van Deventer, J., “Structural evolution of fly ash based geopolymers in alkaline environments”, Industrial and Engineering Chemistry Research, V. 47, No. 9, 2008, pp. 2991-2999.
28. Temuujin, J., Minjigmaa, A., Lee, M., Chen-Tan, N., and Van Riessen, A., “Characterization of Class F Fly Ash Geopolymer Pastes Immersed in Acid and Alkaline Solutions”, Cement and Concrete Composites, V. 33, No. 10, 2011, pp. 1086-1091.
29. Palomo, A., Blanco-Varela, M., Granizo, M., Puertas, F., Vazquez, T., and Grutzeck, M., “Chemical Stability of Cementitious Materials based on Metakaolin”, Cement and Concrete Research, V. 29, No. 7, 1999, pp. 997-1004.
30. Bakharev, T., “Durability of Geopolymer Materials in Sodium and Magnesium Sulfate Solutions”, Cement and Concrete Research, V. 35, No. 6, 2005, pp. 1233-1246.
31. Ismail, I., Bernal, S., Provis, J., Hamdan, S., and van Deventer, J., “Microstructural Changes in Alkali Activated Fly Ash/Slag Geopolymers with Sulfate Exposure”, Materials and Structures, V. 46, No. 3, 2013, pp. 361-373.
32. Steiger, M., Linnow, K., Ehrhardt, D., and Rohde, M., “Decomposition Reactions of Magnesium Sulfate Hydrates and Phase Equilibria in the MgSO4–H2O and Na+–Mg2+–Cl−–SO42−–H2O Systems with Implications for Mars”, Geochimica et Cosmochimica Acta, V. 75,No. 12, 2011, pp. 3600-3626.