The Effect of Alkaline Activator on Workability and Compressive Strength of Alkali-Activated Slag Concrete

Document Type : Research Article

Authors

Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran

Abstract

In this study, experimental results on alkali activated slag (AAS) concrete was assessed to achieve the optimum strength and workability. The alkali contents of Na2O to activate slag in concrete were equal to 3.5, 4.5, 5.5, 6.5 and 7.5 % by mass of slag and silicate moduli of alkali solution varied from 0.45, 0.65, 0.85 and 1.05. The compressive strength test of concrete specimens over 7, 28 and 90 days was measured. To evaluate the concrete workability, the slump of fresh concrete and the setting time of paste were also examined. The results showed that in the proposed range of activation, by increasing the amount of alkali concentration as well as silicate modulus in activator solutions, the workability and compressive strength increased but the setting time of paste reduced. Optimum values for the preparation of AAS mixtures with suitable compressive strength and desirable workability are suggested based on the results.

Highlights

[1] P.-C. Aı̈tcin, Cements of yesterday and today: concrete of tomorrow, Cement and Concrete research, 30(9) (2000) 1349-1359.

[2] J.L. Provis, J.S. van Deventer, Alkali activated materials, Springer, 2014.

[3] M. Taylor, C. Tam, D. Gielen, Energy efficiency and CO2 emissions from the global cement industry, Korea, 50(2.2) (2006) 61.67.

[4] E. Gartner, Industrially interesting approaches to “low- CO2” cements, Cement and Concrete research, 34(9) (2004) 1489-1498.

[5] F. Pacheco-Torgal, J. Labrincha, C. Leonelli, A. Palomo, P. Chindaprasit, Handbook of alkali-activated cements, mortars and concretes, Elsevier, 2014.

[6] P. Duxson, J.L. Provis, G.C. Lukey, J.S. Van Deventer, The role of inorganic polymer technology in the development of ‘green concrete’, Cement and Concrete Research, 37(12) (2007) 1590-1597.

[7] A.A.M. Neto, M.A. Cincotto, W. Repette, Drying and autogenous shrinkage of pastes and mortars with activated slag cement, Cement and Concrete Research, 38(4) (2008) 565-574.

[8] D. Krizan, B. Zivanovic, Effects of dosage and modulus of water glass on early hydration of alkali-slag cements, Cement and Concrete Research, 32(8) (2002) 1181-1188.

[9] M.-c. Chi, J.-j. Chang, R. Huang, Strength and drying shrinkage of alkali-activated slag paste and mortar, Advances in Civil Engineering, 2012 (2012).

[10] F. Collins, J. Sanjayan, Effect of pore size distribution on drying shrinking of alkali-activated slag concrete, Cement and Concrete Research, 30(9) (2000) 1401-1406.

[11] F. Puertas, M. Palacios, T. Vázquez, Carbonation process of alkali-activated slag mortars, Journal of Materials Science, 41(10) (2006) 3071-3082.

[12] T. Bakharev, J.G. Sanjayan, Y.-B. Cheng, Alkali activation of Australian slag cements, Cement and Concrete Research, 29(1) (1999) 113-120.

[13] C.D. Atis, C. Bilim, Ö. Çelik, O. Karahan, Influence of activator on the strength and drying shrinkage of alkali-activated slag mortar, Construction and building materials, 23(1) (2009) 548-555.

[14] N. Marjanovic, M. Komljenovic, Z. Bašcarevic, V. Nikolic, R. Petrovic, Physical-mechanical and microstructural properties of alkali-activated fly ash-blast furnace slag blends, Ceramics International, 41(1) (2015) 1421-1435.

[15] T. Bakharev, J. Sanjayan, Y.-B. Cheng, Effect of elevated temperature curing on properties of alkali-activated slag concrete, Cement and concrete research, 29(10) (1999) 1619-1625.

[16] T. Bakharev, Geopolymeric materials prepared using Class F fly ash and elevated temperature curing, Cement and Concrete Research, 35(6) (2005) 1224-1232.

[17] S.-D. Wang, K.L. Scrivener, P. Pratt, Factors affecting the strength of alkali-activated slag, Cement and Concrete Research, 24(6) (1994) 1033-1043.

[18] M. Chi, R. Huang, Binding mechanism and properties of alkali-activated fly ash/slag mortars, Construction and Building Materials, 40 (2013) 291-298.

[19] BS 1881: Part 120: 1983, Method for Determination of Compressive Strength of Concrete Cores, BSI, UK; 1983.

[20] ASTM C143-90. Standard test method for slump of hydraulic cement concrete. Annual book of ASTM Standards, vol. 04, United States; 1998.

[21] ASTM C191-08. Standard test methods for time of setting of hydraulic cement by Vicat needle. Annual book of ASTM Standards, vol. 04, United States; 2008.

[22] C. Shi, R.L. Day, Selectivity of alkaline activators for the activation of slags, Cement, Concrete and Aggregates, 18(1) (1996) 8-14.

[23] C. Yip, J. Van Deventer, Microanalysis of calcium silicate hydrate gel formed within a geopolymeric binder, Journal of Materials Science, 38(18) (2003) 3851-3860.

[24] G. Sun, J.F. Young, R.J. Kirkpatrick, The role of Al in C-S-H: NMR, XRD, and compositional results for precipitated samples, Cement and Concrete Research, 36(1) (2006) 18-29.

[25] X. Pardal, I. Pochard, A. Nonat, Experimental study of Si-Al substitution in calcium-silicate-hydrate (CSH) prepared under equilibrium conditions, Cement and Concrete Research, 39(8) (2009) 637-643.

[26] M.B. Haha, G. Le Saout, F. Winnefeld, B. Lothenbach, Influence of activator type on hydration kinetics, hydrate assemblage and microstructural development of alkali activated blast-furnace slags, Cement and Concrete Research, 41(3) (2011) 301-310.

[27] W.-C. Wang, H.-Y. Wang, M.-H. Lo, The fresh and engineering properties of alkali activated slag as a function of fly ash replacement and alkali concentration, Construction and Building Materials, 84 (2015) 224- 229.

[28] F. Collins, J. Sanjayan, Workability and mechanical properties of alkali activated slag concrete, Cement and concrete research, 29(3) (1999) 455-458.

Keywords

References

[1] P.-C. Aı̈tcin, Cements of yesterday and today: concrete of tomorrow, Cement and Concrete research, 30(9) (2000) 1349-1359.
[2] J.L. Provis, J.S. van Deventer, Alkali activated materials, Springer, 2014.
[3] M. Taylor, C. Tam, D. Gielen, Energy efficiency and CO2 emissions from the global cement industry, Korea, 50(2.2) (2006) 61.67.
[4] E. Gartner, Industrially interesting approaches to “low- CO2” cements, Cement and Concrete research, 34(9) (2004) 1489-1498.
[5] F. Pacheco-Torgal, J. Labrincha, C. Leonelli, A. Palomo, P. Chindaprasit, Handbook of alkali-activated cements, mortars and concretes, Elsevier, 2014.
[6] P. Duxson, J.L. Provis, G.C. Lukey, J.S. Van Deventer, The role of inorganic polymer technology in the development of ‘green concrete’, Cement and Concrete Research, 37(12) (2007) 1590-1597.
[7] A.A.M. Neto, M.A. Cincotto, W. Repette, Drying and autogenous shrinkage of pastes and mortars with activated slag cement, Cement and Concrete Research, 38(4) (2008) 565-574.
[8] D. Krizan, B. Zivanovic, Effects of dosage and modulus of water glass on early hydration of alkali-slag cements, Cement and Concrete Research, 32(8) (2002) 1181-1188.
[9] M.-c. Chi, J.-j. Chang, R. Huang, Strength and drying shrinkage of alkali-activated slag paste and mortar, Advances in Civil Engineering, 2012 (2012).
[10] F. Collins, J. Sanjayan, Effect of pore size distribution on drying shrinking of alkali-activated slag concrete, Cement and Concrete Research, 30(9) (2000) 1401-1406.
[11] F. Puertas, M. Palacios, T. Vázquez, Carbonation process of alkali-activated slag mortars, Journal of Materials Science, 41(10) (2006) 3071-3082.
[12] T. Bakharev, J.G. Sanjayan, Y.-B. Cheng, Alkali activation of Australian slag cements, Cement and Concrete Research, 29(1) (1999) 113-120.
[13] C.D. Atis, C. Bilim, Ö. Çelik, O. Karahan, Influence of activator on the strength and drying shrinkage of alkali-activated slag mortar, Construction and building materials, 23(1) (2009) 548-555.
[14] N. Marjanovic, M. Komljenovic, Z. Bašcarevic, V. Nikolic, R. Petrovic, Physical-mechanical and microstructural properties of alkali-activated fly ash-blast furnace slag blends, Ceramics International, 41(1) (2015) 1421-1435.
[15] T. Bakharev, J. Sanjayan, Y.-B. Cheng, Effect of elevated temperature curing on properties of alkali-activated slag concrete, Cement and concrete research, 29(10) (1999) 1619-1625.
[16] T. Bakharev, Geopolymeric materials prepared using Class F fly ash and elevated temperature curing, Cement and Concrete Research, 35(6) (2005) 1224-1232.
[17] S.-D. Wang, K.L. Scrivener, P. Pratt, Factors affecting the strength of alkali-activated slag, Cement and Concrete Research, 24(6) (1994) 1033-1043.
[18] M. Chi, R. Huang, Binding mechanism and properties of alkali-activated fly ash/slag mortars, Construction and Building Materials, 40 (2013) 291-298.
[19] BS 1881: Part 120: 1983, Method for Determination of Compressive Strength of Concrete Cores, BSI, UK; 1983.
[20] ASTM C143-90. Standard test method for slump of hydraulic cement concrete. Annual book of ASTM Standards, vol. 04, United States; 1998.
[21] ASTM C191-08. Standard test methods for time of setting of hydraulic cement by Vicat needle. Annual book of ASTM Standards, vol. 04, United States; 2008.
[22] C. Shi, R.L. Day, Selectivity of alkaline activators for the activation of slags, Cement, Concrete and Aggregates, 18(1) (1996) 8-14.
[23] C. Yip, J. Van Deventer, Microanalysis of calcium silicate hydrate gel formed within a geopolymeric binder, Journal of Materials Science, 38(18) (2003) 3851-3860.
[24] G. Sun, J.F. Young, R.J. Kirkpatrick, The role of Al in C-S-H: NMR, XRD, and compositional results for precipitated samples, Cement and Concrete Research, 36(1) (2006) 18-29.
[25] X. Pardal, I. Pochard, A. Nonat, Experimental study of Si-Al substitution in calcium-silicate-hydrate (CSH) prepared under equilibrium conditions, Cement and Concrete Research, 39(8) (2009) 637-643.
[26] M.B. Haha, G. Le Saout, F. Winnefeld, B. Lothenbach, Influence of activator type on hydration kinetics, hydrate assemblage and microstructural development of alkali activated blast-furnace slags, Cement and Concrete Research, 41(3) (2011) 301-310.
[27] W.-C. Wang, H.-Y. Wang, M.-H. Lo, The fresh and engineering properties of alkali activated slag as a function of fly ash replacement and alkali concentration, Construction and Building Materials, 84 (2015) 224- 229.
[28] F. Collins, J. Sanjayan, Workability and mechanical properties of alkali activated slag concrete, Cement and concrete research, 29(3) (1999) 455-458.
AUT Journal of Civil Engineering
Volume 1, Issue 1
May 2017
Pages 55-60

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