Influence of Fly Ash and Its Partial Replacement by Slag on the Leaching Behavior of Blended Cement Pastes
Publication: Journal of Materials in Civil Engineering
Volume 29, Issue 10
Abstract
An accelerated leaching experiment, using 6M solution, on specimens of pure cement paste, binary cement paste with different fly ash contents (20, 30, and 50%), and ternary cement paste with the replacement of 10, 20, and 30% fly ash by slag was conducted to investigate the influence of fly ash and its partial replacement by slag on the leaching behavior of blended cement pastes. The leaching depth, porosity, calcium-silicon mass ratio (), phase composition, and microstructure morphology of the specimens were characterized by using the phenolphthalein indicator, saturation-drying weighing, scanning electron microscopy with energy dispersive spectrometer (SEM/EDS), and X-ray diffraction (XRD). Results show that higher fly ash content mixed in pure cement paste causes a greater leaching depth, with slower microstructure deterioration, lower porosity increment, and reduction of and calcium hydroxide content. Higher replacement of fly ash by slag in binary cement paste leads to a more compact microstructure and higher after complete leaching of calcium hydroxide. The fly ash can reduce the leaching degree of pure cement paste but accelerate its leaching process; however, the partial replacement of fly ash by slag in blended cement paste not only improves its compactness and the stability of its microstructure, but also slows down its leaching process. The ternary cement paste with a water-binder ratio of 0.45, 20% fly ash, and 30% slag has the optimum leaching resistance.
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Acknowledgments
The study of this paper is financially supported by the National Natural Science Foundation of China (51378262) and the Natural Science Foundation of Jiangsu Province of China (BK20141396).
References
Bellégo, L., Gérard, B., and Pijaudier-Cabot, G. (2001). “Mechanical analysis of concrete structures subjected to an aggressive water attack.” Fract. Mech. Concr. Struct., 1-2, 239–246.
Berger, S., Aouad, G., Cau, D. C. C., Le, B. P., and Damidot, D. (2013). “Leaching of calcium sulfoaluminate cement pastes by water at regulated pH and temperature: Experimental investigation and modeling.” Cem. Concr. Res., 53, 211–220.
Berodier, E., and Scrivener, K. (2015). “Evolution of pore structure in blended systems.” Cem. Concr. Res., 73, 25–35.
Cai, X., He, Z., Shao, Y., and Sun, H. (2016). “Macro- and micro-characteristics of cement binders containing high volume fly ash subject to electrochemical accelerated leaching.” Constr. Build. Mater., 116, 25–35.
Cheng, A., Chao, S., and Lin, W. (2013). “Effects of leaching behavior of calcium ions on compression and durability of cement-based materials with mineral admixtures.” Materials, 6(5), 1851–1872.
Choi, Y. S., and Yang, E. I. (2013). “Effect of calcium leaching on the pore structure, strength, and chloride penetration resistance in concrete specimens.” Nucl. Eng. Des., 259, 126–136.
Cwirzen, A., Punkki, J., Engblom, R., and Habermehl-Cwirzen, K. (2014). “Effects of curing: Comparison of optimised alkali-activated PC-FA-BFS and PC concretes.” Mag. Concr. Res., 66(6), 315–323.
Feng, P., Miao, C. W., and Bullard, J. W. (2014). “A model of phase stability, microstructure and properties during leaching of portland cement binders.” Cem. Concr. Compos., 49, 9–19.
Fernández-Jiménez, A., and Puertas, F. (1997). “Alkali-activated slag cements: Kinetic studies.” Cem. Concr. Res., 27(3), 359–368.
Forster, A. M., Szadurski, E. M., and Banfill, P. F. G. (2014). “Deterioration of natural hydraulic lime mortars. I: Effects of chemically accelerated leaching on physical and mechanical properties of uncarbonated materials.” Constr. Build. Mater., 72, 199–207.
Gedam, B. A., Bhandari, N. M., and Upadhyay, A. (2016). “Influence of supplementary cementitious materials on shrinkage, creep, and durability of high-performance concrete.” J. Mater. Civ. Eng., 28(4), 04015173.
Goni, S., Frias, M., Vigil, D. L. R., and Garcia, R. (2013). “Sodium chloride effect on durability of ternary blended cement. Microstructural characterization and strength.” Compos. Part B-Eng., 54, 163–168.
Haga, K., Shibata, M., Hironaga, M., Tanaka, S., and Nagasaki, S. (2005a). “Change in pore structure and composition of hardened cement paste during the process of dissolution.” Cem. Concr. Res., 35(5), 943–950.
Haga, K., Sutou, S., Hironaga, M., Tanaka, S., and Nagasaki, S. (2005b). “Effects of porosity on leaching of Ca from hardened ordinary portland cement paste.” Cem. Concr. Res., 35(9), 1764–1775.
Han, F., Liu, R., and Yan, P. (2014). “Effect of fresh water leaching on the microstructure of hardened composite binder pastes.” Constr. Build. Mater., 68, 630–636.
Heukamp, F. H., Ulm, F. J., and Germaine, J. T. (2005). “Does calcium leaching increase ductility of cementitious materials? Evidence from direct tensile tests.” J. Mater. Civ. Eng., 307–312.
Jain, J., and Neithalath, N. (2009). “Analysis of calcium leaching behavior of plain and modified cement pastes in pure water.” Cem. Concr. Compos., 31(3), 176–185.
Jeong, Y., Park, H., Jun, Y., Jeong, J., and Oh, J. E. (2015). “Microstructural verification of the strength performance of ternary blended cement systems with high volumes of fly ash and GGBFS.” Constr. Build. Mater., 95, 96–107.
Kandasamy, S., and Shehata, M. H. (2014). “The capacity of ternary blends containing slag and high-calcium fly ash to mitigate alkali silica reaction.” Cem. Concr. Compos., 49, 92–99.
Kim, G., Nam, J., Lee, E., and Koo, K. (2011). “Analysis of hydration heat and autogenous shrinkage of high-strength mass concrete.” Mag. Concr. Res., 63(5), 377–389.
Kim, S., Yang, K., Lee, K., and Yi, S. (2016). “Mechanical properties and adiabatic temperature rise of low heat concrete using ternary blended cement.” Comput. Concr., 17(2), 271–280.
Koleva, D. A., Boshkov, N., Breugel, V. K., and Wit, J. H. W. D. (2011). “Steel corrosion resistance in model solutions, containing waste materials.” Electrochimica Acta., 58, 628–646.
Komljenovic, M. M., Bascarevic, Z., Marjanovic, N., and Nikolic, V. (2012). “Decalcification resistance of alkali-activated slag.” J. Hazard. Mater., 233, 112–121.
Le Bellégo, C., Pijaudier-Cabot, G., Gerard, B., Dube, J. F., and Molez, L. (2003). “Coupled mechanical and chemical damage in calcium leached cementitious structures.” J. Eng. Mech., 333–341.
Lee, K. (2011). “Study on hydration heat of blended belite binder.” J. Korea Concr. Inst., 23(2), 145–150.
Li, X., and Yan, P. (2010). “Microstructural variation of hardened cement-fly ash pastes leached by soft water.” Sci. China Technol. Sci., 53(11), 3033–3038.
Lin, C., Zhu, W., and Han, J. (2013). “Strength and leachability of solidified sewage sludge with different additives.” J. Mater. Civ. Eng., 1594–1601.
Liu, R., Zhang, B., and Yan, P. (2013). “Microstructural variation of hardened cement-slag pastes leached by soft water.” J. Chin. Ceram. Soc., 11, 1487–1492.
López, M. M., Pineda, Y., and Gutiérrez, O. (2015). “Evaluation of durability and mechanical properties of the cement mortar added with slag blast furnace.” Procedia Mater. Sci., 9, 367–376.
Lu, C., Yang, H., Liu, W., Mei, G., Wang, H., and Ge, X. (2014). “Effect of fly ash on compressive strength degradation due to calcium leaching procedure.” Adv. Cem. Res., 26(3), 137–144.
Natali, S. I., Pelosato, R., Botta, D., and Dotelli, G. (2002). “Chemistry and microstructure of cement pastes admixed with organic liquids.” J. Eur. Ceram. Soc., 22(9–10), 1463–1473.
Paine, K. A., Zheng, L., and Dhir, R. K. (2005). “Experimental study and modelling of heat evolution of blended cements.” Adv. Cem. Res., 17(3), 121–132.
Pavlik, V. (2000). “Water extraction of chloride, hydroxide and other ions from hardened cement pastes.” Cem. Concr. Res., 30(6), 895–906.
Phung, Q. T., Maes, N., Jacques, D., De, S. G., and Ye, G. (2016). “Investigation of the changes in microstructure and transport properties of leached cement pastes accounting for mix composition.” Cem. Concr. Res., 79, 217–234.
Puertas, F., Goni, S., Hernandez, M. S., Varga, C., and Guerrero, A. (2012). “Comparative study of accelerated decalcification process among C3S, grey and white cement pastes.” Cem. Concr. Compos., 34(3), 384–391.
Rashad, A. M. (2014). “A comprehensive overview about the influence of different admixtures and additives on the properties of alkali-activated fly ash.” Mater. Des., 53, 1005–1025.
RILEM. (1984). “Absorption of water by immersion under vacuum.” Mater. Struct., 17, 391–394.
Rozière, E., and Loukili, A. (2011). “Performance-based assessment of concrete resistance to leaching.” Cem. Concr. Compos., 33(4), 451–456.
Rozière, E., Loukili, A., El-Hachem, R., and Grondin, F. (2009). “Durability of concrete exposed to leaching and external sulphate attacks.” Cem. Concr. Res., 39(12), 1188–1198.
Sarkar, S., Mahadevan, S., Meeussen, J. C. L., Sloot, H. V. D., and Kosson, D. S. (2012). “Sensitivity analysis of damage in cement materials under sulfate attack and calcium leaching.” J. Mater. Civ. Eng., 430–440.
Schneider, M., Romer, M., Tschudin, M., and Bolio, H. (2011). “Sustainable cement production—Present and future.” Cem. Concr. Res., 41(7), 642–650.
Taylor, R., Richardson, I. G., and Brydson, R. M. D. (2010). “Composition and microstructure of 20-year-old ordinary portland cement-ground granulated blast-furnace slag blends containing 0 to 100% slag.” Cem. Concr. Res., 40(7), 971–983.
Torres-Acosta, A. A., and Martinez-Madrid, M. (2003). “Residual life of corroding reinforced concrete structures in marine environment.” J. Mater. Civ. Eng., 344–353.
Van Der Sloot, H. A. (2000). “Comparison of the characteristic leaching behavior of cements using standard (EN 196-1) cement mortar and an assessment of their long-term environmental behavior in construction products during service life and recycling.” Cem. Concr. Res., 30(7), 1079–1096.
Wan, K. S., Li, Y., and Sun, W. (2013). “Experimental and modelling research of the accelerated calcium leaching of cement paste in ammonium nitrate solution.” Constr. Build. Mater., 40, 832–846.
Wu, K., Shi, H., Xu, L., Ye, G., and De, S. G. (2016). “Microstructural characterization of ITZ in blended cement concretes and its relation to transport properties.” Cem. Concr. Res., 79, 243–256.
Yang, H., Jiang, L. H., and Zhang, Y. (2010). “The effect of fly ash on calcium leaching properties of cement pastes in ammonium chloride solution.” Adv. Mater. Res., 163–167, 1162–1170.
Yang, H., Jiang, L. H., Zhang, Y., and Pu, Q. (2013). “Flexural strength of cement paste beam under chemical degradation: Experiments and simplified modeling.” J. Mater. Civ. Eng., 555–562.
Zhang, T., Liu, X., Wei, J., and Yu, Q. (2014). “Influence of preparation method on the performance of ternary blended cements.” Cem. Concr. Compos., 52, 18–26.
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Journal of Materials in Civil Engineering
Volume 29 • Issue 10 • October 2017
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©2017 American Society of Civil Engineers.
History
Received: Sep 28, 2016
Accepted: Mar 15, 2017
Published online: Jul 21, 2017
Published in print: Oct 1, 2017
Discussion open until: Dec 21, 2017
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