Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 31106
Effect of Incorporating Silica Fume in Fly Ash Geopolymers

Authors: Suresh Thokchom, Debabrata Dutta, Somnath Ghosh


This paper presents results of an experimental study performed to investigate effect of incorporating silica fume on physico-mechanical properties and durability of resulting fly ash geopolymers. Geopolymer specimens were prepared by activating fly ash incorporated with additional silica fume in the range of 2.5% to 5%, with a mixture of sodium hydroxide and sodium silicate solution having Na2O content of 8%. For studying durability, 10% magnesium sulphate solution was used to immerse the specimens up to a period of 15 weeks during which visual observation, weight changes and strength changes were monitored regularly. Addition of silica fume lowers performance of geopolymer pastes. However, in mortars, addition of silica fume significantly enhanced physico-mechanical properties and durability.

Keywords: Durability, fly ash, Geopolymer, silica fume, compressive strength, sorptivity, apparent porosity

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3242


[1] J. Davitovits, "Properties of geopolymer cements," Proceedings of the first International conference on alkaline cements and concretes vol. 1, SRIBM, Kiev, 1994, pp. 131-149.
[2] A. Palomo, M.W. Gruztek, M.T. Blanco, "Alkali activated fly ashes. A cement for the future," Cement and Concrete Research 29 1999,pp. 1323-1329.
[3] T. Bakharev, "Resistance of geopolymer materials to acid attack," Cem. & Conc. Research 35, 2005, pp. 658-670.
[4] T. Bakharev, "Durability of geopolymer materials in sodium and magnesium sulphate solutions," Cement and Concrete Research 35, 2005, pp.1233-1246.
[5] X.J. Song, M. Marosszeky, M. Brungs, R. Munn, " Durability of fly ash based geopolymer concrete against sulphuric acid attack," 10 DBMC International conference on durability of building materials and components, Lyon, France, 2005.
[6] S. Thokchom, P. Ghosh, S. Ghosh, "Resistance of fly ash based geopolymer mortars in sulphuric acid," Journal of Engineering and Applied Sciences 4(1),2009, pp. 65-70.
[7] S. Thokchom, P. Ghosh, S. Ghosh, "Performance of Fly ash based Geopolymer mortars in sulphate solution," Journal of Engineering Science and Technology Review 3(1), 2010, pp.36-40.
[8] S. Thokchom, P. Ghosh, S. Ghosh, "Durability of Fly ash Geopolymer mortars in Nitric acid-effect of Alkali (Na2O) content," Journal of Civil Engineering and Management 17(3),2011, pp. 393-399.
[9] Fernandez-Jimenez, I.garcia-Lodeiro, A. Palomo, " Durability of alkali activated fly ash cementitious materials," J. Mater Sci 42, 2007, pp. 3055-3065.
[10] S.E. Wallah, B.V. Rangan, "Low calcium fly ash based geopolymer concrete: Long term properties," Research report GC2, Curtin University of Technology, Australia, 2006.
[11] T. Bakharev, "Geopolymeric materials prepared using class F fly ash and elevated temperature curing," Cement and Concrete Research 35, 2005, pp. 1224-1232.
[12] T. Bakharev, "Thermal behaviour of geopolymers prepared using class F fly ash and elevated temperature curing," Cement and Concrete Research 36, 2006, pp. 1134-1147.
[13] D.L.Y. Kong, J.G. Sanjayan, "Effect of elevated Effect of elevated temperatures on geopolymer paste, mortar and concrete," Cement and Concrete Research, 40, 2010, pp. 334-339.
[14] D.R.M. Brew, K.J.D. MacKenzie, "Geopolymer synthesis using silica fume and sodium aluminate," J Mater Sci 42, 2007, pp. 3990-3993.
[15] R. Thakur, S. Ghosh, "Fly ash based geopolymer composites," Proceedings of 10th NCB International seminar on cement and building materials, New Delhi, India 3, 2007, pp. 442-451.
[16] S. Thokchom, P. Ghosh, S. Ghosh, "Porosity and Sorptivity on Performance of Fly Ash Based Geopolymer Mortars in Nitric Acid", International Journal of Applied Engineering Research, .4(11), 2009, pp.2085-2092.
[17] B.B. Sabir, S, Wild, M. O-Farrel, "A water sorptivity test for mortar and concrete," Materials and Structures, 31, 1998, pp.568-574.
[18] A. Allahverdi, F. Skvara, "Sulfuric acid attack on hardened paste of geopolymeric cements part 1,Mechanism of corrosion at relatively high concentrations,Ceramics-Silikaty 49 (4), 2005, pp.225-229.
[19] F. Rendell, R. Jauberthie, "The deterioration of mortar in sulphate environments. Cement & Concrete Research 13, 1999, pp. 321-327.