Role of Gypsum in the Strength Development of Fly Ashes with Lime
Publication: Journal of Materials in Civil Engineering
Volume 23, Issue 2
Abstract
The strength of fly ash mixture often needs to be enhanced for its better utilization in geotechnical and environmental applications. Many fly ashes often improve their strength with lime but may not meet the requirements. Gypsum, which reduces the lime leachability, further improves the strength. An attempt is made in this paper to study the effect of gypsum on the strength development of two Class F fly ashes with different lime contents after curing them for different periods. The sustainability of improved strength has been examined after soaking the cured specimens in water and with different leachates containing heavy-metal ions. The strength of both the fly ashes investigated improved markedly up to a particular amount of the lime content, which can be taken as optimum lime content, and thereafter the improvement is gradual. The improvement in strength at higher lime contents continues for a longer period (even up to 180 days). Gypsum accelerates the gain in strength for lime-stabilized fly ashes, particularly in the initial curing periods at about optimum lime content. At high lime contents gypsum attributes very high strength after curing for long periods mainly due to the alteration of fly ash lime reaction compounds. Gypsum not only improves the reduction in the loss of strength due to soaking even at low curing periods but also improves the durability of stabilized fly ashes due to repeated cycles of wetting and drying.
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Acknowledgments
The writers are grateful to Dr. Baig M. Y. A., Retired Professor, SVUCE, for his assistance in revising the paper. The writers would like to thank the reviewers for their critical review and constructive comments.
References
Alinnor, I. J. (2007). “Adsorption of heavy metals from aqueous solutions by fly ash.” Fuel, 86(5–6), 853–857.
Antiohos, S., and Tsimas, S. (2004). “Activation of fly ash cementitious systems in the presence of quicklime: Part I. Compressive strength and pozzolanic reaction rate.” Cem. Concr. Res., 34, 769–779.
ASTM. (2003). “Standard test methods for wetting and drying compacted soil-cement mixtures.” D559, West Conshohocken, Pa.
ASTM. (2006). “Standard test method for unconfined compressive strength of cohesive soil.” D2166, West Conshohocken, Pa.
ASTM. (2008). “Standard specification for coal fly ash and raw or calcined natural pozzolan for use in concrete.” C618, West Conshohocken, Pa.
ASTM. (2009). “Standard test methods for unconfined compressive strength of compacted soil-lime mixtures.” D5102, West Conshohocken, Pa.
Ayala, J., Bianco, F., Garcia, P., Rodriguez, P., and Sancho, J. (1998). “Asturian fly ash as a heavy metals removal material.” Fuel, 77(11), 1147–1154.
Bhatnagar, J. M., Goel, R. K., Hiralal, E. S., and Hajele, R. B. (1988). “Utilization of fly ash in the manufacture of clay flooring/terracing tiles from alluvial soils.” National Workshop on Utilization of Fly Ash, A55–A58.
Bin-Shafique, S., Edil, T. B., Benson, C. H., and Senol, A. (2004). “Incorporating a fly ash stabilized layer into pavement design.” Proc., Inst. Civ. Eng., Geotechnical Engineering, 157(GE4), 239–249.
Bou, E., Quereda, M. F., Lever, D., Boccaccini, A. R., and Cheeseman, C. R. (2009). “Production of pulverised fuel ash tiles using conventional ceramic production processes.” Adv. Appl. Ceram., 108(1), 44–49.
Cabrera, J. G., and Gray, M. N. (1973). “Specific surface, pozzolanic activity and composition of pulverized fuel ash.” Fuel, 52, 213–219.
DiGioa, A. M., and Nuzzo, W. C. (1972). “Fly ash as structural fill.” J. Power Div., 98, 77–92.
Faber, J. H., and DiGioa, A. M. (1974). “Use of fly ash in embankment construction.” Transportation Research Board, Washington, DC, 574, 13–19.
Ganesh, K. B., and Siva, N. R. G. (1993). “Efficiency of fly ash in concrete.” Cem. Concr. Compos., 15, 223–229.
Ghosh, A. (1996). “Environmental and engineering characteristics of stabilized low lime fly ash.” Ph.D. thesis, Indian Institute of Technology, Kanpur, India.
Ghosh, A., and Subbarao, C. (2006a). “Leaching of lime from fly ash stabilised with lime and gypsum.” J. Mater. Civ. Eng., 18(1), 106–115.
Ghosh, A., and Subbarao, C. (2006b). “Tensile strength bearing ratio and slake durability of class F fly ash stabilized with lime and gypsum.” J. Mater. Civ. Eng., 18(1), 18–27.
Ghosh, A., and Subbarao, C. (2007). “Shear strength characteristics of class F fly ash modified with lime and gypsum.” J. Geotech. Geoenviron. Eng., 133(7), 757–766.
Gray, D. H., and Lin, Y. K. (1972). “Engineering properties of compacted fly ash.” J. Soil Mech. and Found. Div., 9(SM4), 361–377.
Héquet, V., Ricou, P., Lecuyer, I., and Le Cloirec, P. (2001). “Removal of and in aqueous solution by sorption onto mixed fly ash.” Fuel, 80(6), 851–856.
Hewlett, P. C. (1998). LEA’s chemistry of cement and concrete, 4th Ed., Reed Educational and Professional Publishing, Ltd., Edward Arnold, New York.
Horiuchi, S., Kawaguchi, M., and Yasuhara, K. (2000). “Effective use of fly ash slurry as fill material.” J. Hazard. Mater., 76, 301–337.
Indraratna, B., Nutalaya, P., Koo, K. S., and Kuganenthira, N. (1991). “Engineering behavior of low carbon, pozzolanic fly ash and its potential as a construction fill.” Can. Geotech. J., 28, 542–555.
Jaturapitakkul, C., Kiattikomol, K., Sata, V., and Leekeeratikul, T. (2004). “Use of ground coarse fly ash as a replacement of silica fume in producing high strength concrete.” Cem. Concr. Res., 34, 549–555.
JCPDS. (1999). “Joint Committee for Powder Diffraction Studies. International Centre for Diffraction Data (ICDD).” The Powder Diffraction File, Newtown Square, Pa.
Jiang, W., and Roy, D. M. (1992). “Hydrothermal processing of new fly ash cement.” Am. Ceram. Soc. Bull., 71, 642–647.
Kim, B., Prezzi, M., and Salgado, R. (2005). “Geotechnical properties of fly and bottom ash mixtures for use in highway embankments.” J. Geotech. Geoenviron. Eng., 131(7), 914–924.
Leelavathamma, B., Mini, K. M., and Pandian, N. S. (2005). “California bearing ratio behavior of soil-stabilized class F fly ash systems.” J. Test. Eval., 33(6), 406–410.
Leonards, G. A., and Bailey, B. (1982). “Pulverized coal ash as structural fill.” J. Geotech. Engrg. Div., 108(GT4), 517–531.
Ma, W., and Brown, P. W. (1997). “Hydrothermal reactions of fly ash with and .” Cem. Concr. Res., 27(8), 1237–1248.
McCarthy, M. J., and Dhir, R. K. (1999). “Towards maximizing the use of fly ash as a binder.” Fuel, 78, 121–132.
Mehta, P. K. (1985). “Influence of fly ash characteristics on the strength of portland-fly ash mixtures.” Cem. Concr. Res., 15, 669–674.
Mustafa, S., Ismail, O. Y., and Mustafa, T. (2009). “Transport and mechanical properties of self-consolidating concrete with high volume fly ash.” Cem. Concr. Compos., 31, 99–106.
Plowman, C. (1984). “The chemistry of PFA in concrete—A review of current knowledge.” Proc., 2nd Int. Conf. on Ash Technology and Marketing, 437–443.
Rai, D., Eary, L. E., and Zachara, J. M. (1989). “Environmental chemistry of chromium.” Sci. Total Environ., 86, 15–23.
Raymond, S. (1961). “Pulverized fly ash as embankment material.” Proc.-Inst. Civ. Eng., 19, 515–536.
Sharma, R. C. (1989). “Rapid method for assessment of reactivity of Indian fly ashes.” NCB Quest, 16, 16–23.
Sherwood, P. T., and Ryley, M. D. (1966). “Use of stabilized pulverized fuel ash in road construction.” Road Research Laboratory Report Ministry of Transport, U.K., 49, 1–44.
Siddique, R. (2003). “Effect of fine aggregate replacement with class F fly ash on the mechanical properties of concrete.” Cem. Concr. Res., 33, 539–547.
Singh, M., and Garg, M. (1999). “Cementitious binder from fly ash and other industrial wastes.” Cem. Concr. Res., 29, 309–314.
Singh, S. R., and Panda, A. P. (1996). “Utilization of fly ash in geotechnical construction.” Proc., Indian Geotechnical Conf., Vol. 1, 227–230.
Sivapullaiah, P. V., Prashanth, J. P., Sridharan, A., and Narayana, B. V. (1998). “Reactive silica and strength of fly ashes.” Geotech. Geologic. Eng., 16, 239–250.
Sridharan, A., and Sivapullaiah, P. V. (2005). “Mini compaction test apparatus for fine grained soils.” Geotech. Test. J., 28(3), 240–246.
Tsimas, S., and Tsima, A. M. (2005). “High-calcium fly ash as a fourth constituent in concrete: Problems, solutions and perspectives.” Cem. Concr. Compos., 27, 231–237.
Xu, A., and Sarkar, S. L. (1994). “Microstructural development in high-volume fly-ash system.” J. Mater. Civ. Eng., 6(1), 117–136.
Yen, T., Hsu, T. H., Liu, Y. W., and Chen, S. H. (2007). “Influence of class F fly ash on the abrasion-erosion resistance of high-strength concrete.” Constr. Build. Mater., 21(2), 458–463.
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© 2011 ASCE.
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Received: Dec 2, 2009
Accepted: Jul 18, 2010
Published online: Jul 29, 2010
Published in print: Feb 2011
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