Effect of Na2O Content on Durability of Geopolymer Mortars in Sulphuric Acid
This paper presents the findings of an
experimental investigation to study the effect of alkali content
in geopolymer mortar specimens exposed to sulphuric acid.
Geopolymer mortar specimens were manufactured from Class F fly
ash by activation with a mixture of sodium hydroxide and sodium
silicate solution containing 5% to 8% Na2O. Durability of specimens
were assessed by immersing them in 10% sulphuric acid solution and
periodically monitoring surface deterioration and depth of
dealkalization, changes in weight and residual compressive strength
over a period of 24 weeks. Microstructural changes in the specimens
were studied with Scanning electron microscopy (SEM) and EDAX.
Alkali content in the activator solution significantly affects the
durability of fly ash based geopolymer mortars in sulphuric acid.
Specimens manufactured with higher alkali content performed better
than those manufactured with lower alkali content. After 24 weeks in
sulphuric acid, specimen with 8% alkali still recorded a residual
strength as high as 55%.
[1] J. Davidovits, "Properties of geopolymer cements",Proc.First
International conference on Alkaline Cements and
Concretes,vol. 1, SRIBM, Kiev, Ukraine, 1994, pp. -131 - 149.
[2] T. Bakharev, "Resistance of geopolymer materials to acid
attack", Cement & Concrete Research 35, 2005 pp.658 - 670.
[3] X. J. Song, M. Marosszeky, M. Brungs, R. Munn, "Durability
of fly ash based Geopolymer concrete against sulphuric acid
attack", presented at 10 DBMC Int. Conference on Durability of
Building Materials and Components, Lyon, France, 2005
[4] 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.
[5] S. Thokchom, P. Ghosh, S. Ghosh, "Resistance of fly ash based
geopolymer mortars in sulfuric acid" J. of Engg. and Applied
sciences", 4(1), 2009 pp. 65-70
[6] S. Thokchom, P. Ghosh, S. Ghosh, " Acid resistance of fly ash
based geopolymer mortars" Int. Journal of recent trends in
Engg."1(6),2009 pp.36-40.
[7] A. Allahverdi, F. Skavara, "Sulfuric acid attack on hardened
paste of Geopolymer cements, Part 1. Mechanism of corrosion at
relatively high concentrations", Ceramics - Silikaty 45 (3)2001
pp.81 - 88.
[8] A. Allahverdi, F. Skavara, "Sulfuric acid attack on hardened
paste of geopolymer cements, Part 2 Corrosion mechanism at
mild and relatively low concentrations, Ceramics-Silikaty 50
(1),2006 pp.1 - 4
[9] A. Allahverdi, F. Skavara, "Nitric acid attack on hardened paste
of geopolymeric cements, Part 1, Ceramics-Silikaty 45 (3),2001
pp.81 -88.
[10] A. Allahverdi, F. Skavara, "Nitric acid attack on hardened paste
of geopolymeric cements, Part 2, Ceramics-Silikaty 45 (4),2001
pp.143-149.
[11] R. N. Thakur, S. Ghosh, "Fly ash based geopolymer composites"
in Proc. 10th NCB International seminar on cement and building
materials, New Delhi,Vol.3,2007,pp.442 - 451.
[12] F. Rendell, R. Jauberthie, "The deterioration of mortar in
sulphate environments" Construction and building materials, 13,
1999, pp.321-327.
[1] J. Davidovits, "Properties of geopolymer cements",Proc.First
International conference on Alkaline Cements and
Concretes,vol. 1, SRIBM, Kiev, Ukraine, 1994, pp. -131 - 149.
[2] T. Bakharev, "Resistance of geopolymer materials to acid
attack", Cement & Concrete Research 35, 2005 pp.658 - 670.
[3] X. J. Song, M. Marosszeky, M. Brungs, R. Munn, "Durability
of fly ash based Geopolymer concrete against sulphuric acid
attack", presented at 10 DBMC Int. Conference on Durability of
Building Materials and Components, Lyon, France, 2005
[4] 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.
[5] S. Thokchom, P. Ghosh, S. Ghosh, "Resistance of fly ash based
geopolymer mortars in sulfuric acid" J. of Engg. and Applied
sciences", 4(1), 2009 pp. 65-70
[6] S. Thokchom, P. Ghosh, S. Ghosh, " Acid resistance of fly ash
based geopolymer mortars" Int. Journal of recent trends in
Engg."1(6),2009 pp.36-40.
[7] A. Allahverdi, F. Skavara, "Sulfuric acid attack on hardened
paste of Geopolymer cements, Part 1. Mechanism of corrosion at
relatively high concentrations", Ceramics - Silikaty 45 (3)2001
pp.81 - 88.
[8] A. Allahverdi, F. Skavara, "Sulfuric acid attack on hardened
paste of geopolymer cements, Part 2 Corrosion mechanism at
mild and relatively low concentrations, Ceramics-Silikaty 50
(1),2006 pp.1 - 4
[9] A. Allahverdi, F. Skavara, "Nitric acid attack on hardened paste
of geopolymeric cements, Part 1, Ceramics-Silikaty 45 (3),2001
pp.81 -88.
[10] A. Allahverdi, F. Skavara, "Nitric acid attack on hardened paste
of geopolymeric cements, Part 2, Ceramics-Silikaty 45 (4),2001
pp.143-149.
[11] R. N. Thakur, S. Ghosh, "Fly ash based geopolymer composites"
in Proc. 10th NCB International seminar on cement and building
materials, New Delhi,Vol.3,2007,pp.442 - 451.
[12] F. Rendell, R. Jauberthie, "The deterioration of mortar in
sulphate environments" Construction and building materials, 13,
1999, pp.321-327.
@article{"International Journal of Architectural, Civil and Construction Sciences:56683", author = "Suresh Thokchom and Partha Ghosh and Somnath Ghosh", title = "Effect of Na2O Content on Durability of Geopolymer Mortars in Sulphuric Acid", abstract = "This paper presents the findings of an
experimental investigation to study the effect of alkali content
in geopolymer mortar specimens exposed to sulphuric acid.
Geopolymer mortar specimens were manufactured from Class F fly
ash by activation with a mixture of sodium hydroxide and sodium
silicate solution containing 5% to 8% Na2O. Durability of specimens
were assessed by immersing them in 10% sulphuric acid solution and
periodically monitoring surface deterioration and depth of
dealkalization, changes in weight and residual compressive strength
over a period of 24 weeks. Microstructural changes in the specimens
were studied with Scanning electron microscopy (SEM) and EDAX.
Alkali content in the activator solution significantly affects the
durability of fly ash based geopolymer mortars in sulphuric acid.
Specimens manufactured with higher alkali content performed better
than those manufactured with lower alkali content. After 24 weeks in
sulphuric acid, specimen with 8% alkali still recorded a residual
strength as high as 55%.", keywords = "Alkali content, acid attack, compressive strength,
geopolymer", volume = "3", number = "3", pages = "167-6", }