Factors affecting early compressive strength of alkali activated fly ash (OPC-free) concrete


  • A. Fernández-Jiménez Instituto de Ciencias de la Construcción Eduardo Torroja (CSIC) (Madrid)
  • A. Palomo Instituto de Ciencias de la Construcción Eduardo Torroja (CSIC) (Madrid)




alkali activation, fly ash, concrete, compressive strength, dosage


This paper presents the findings of experimental research into the chief characteristics of a new type of concrete made solely with alkali activated fly ash (AAFA): i.e., free of ordinary Portland cement (OPC). The results of testing to determine specific properties of the fresh concrete and the development of its mechanical strength showed that most of the factors that affect the manufacture and final properties of Portland cement concrete (water/cement ratio, curing conditions, etc.) also impact the preparation and final quality of this new material. A number of parameters specific to AAFA concrete (nature and concentration of alkali present in the system) were also explored to determine their role in the setting and hardening process.


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(1) Talling, B. y Brandster, J.: “Present state and future of alkali-activated slag concretes”, 3rd International Conference of Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete, Tondheim, SP 114-74 (1989), pp. 1519-1546.

(2) Glukhovsky, V. D., Rostovskaja, G. S. y Rumyna, G.V.: “High strength slag-alkaline cements”, 7th International Congress on the Chemistry of Cement, París, 3, V-164-168 (1980).

(3) Puertas, F.: “Cementos de escorias activadas alcalinamente; situación actual y perspectivas de futuro”, Mater. Construcc., vol 45, nº 239 (1995), pp. 53-64.

(4) Malek, R. I. A. y Roy, D. M.: “Structure and properties of alkaline activated cementitious materials”, 97th annual meeting of the American Ceramic Society, Cincinati, OH, 1995.

(5) Fernández-Jiménez, A., Puertas, F. y Palomo J. G.: “Alkali-Activated Slag Mortars: Mechanical Strength Behaviour”, Cem. Concr. Res., vol. 29 (1999), pp. 1313-1321. doi:10.1016/S0008-8846(99)00154-4

(6) Puertas, F. y Fernández-Jiménez, A.: “Mineralogical and microstructural characterisation of alkali-activated fly ash/slag pastes”, Cem. and Concr. Comp., nº 25 (2003), pp. 287-292.

(7) Davidovits, J.: “Properties of geopolymer cements”, First International Conference of Alkaline Cements and Concretes, Ukraine, Kiev, 1994, pp. 131-149.

(8) Granizo, M. L., Alonso, S., Blanco-Varela, M. T. y Palomo, A.: “Alkaline activation of metakaolin: effect of calcium hydroxide in the products of reaction”, J. Am. Ceram. Soc., nº 85 [1] (2002), pp. 225-231.

(9) Krivenko, P. V., “Alkaline cements”, en P. V. Krivenko (ed.): Alkaline cements and concretes, 1. Vipol Stock Company, Kiev., 1994, pp. 11-129.

(10) Palomo, A., Grutzeck, M-W., Blanco, M. T.: “Alkali-activated fly ashes a cement for the future”, Cem. Concr. Res., vol. 29 (1999), pp. 1323-1329. doi:10.1016/S0008-8846(98)00243-9

(11) Fernández-Jiménez A. y Palomo, A.: “Alkali-activated fly ashes: properties and characteristics”, 11th International Congress on the Chemistry of Cement (Durban, South Africa), vol. 3 (2003), pp. 1332-1340.

(12) Palomo, A., Alonso, S., Fernández-Jiménez, A., Sobrados, I. y Sanz, J.: “Alkaline activation of fly ashes. A 29Si NMR study of the reaction products”, J. Am. Ceramic. Soc., nº 87 [6] (2004), pp. 1141-1145.

(13) Van Jaarsveld, J. G. S., Van Deventer, J. S. J. y Lukey, G. C.: “The effect of composition and temperature on the properties of fly ash and kaolinite-based geopolymers”, Chemical Engineering Journal, vol. 89 (2002), pp. 63-73. doi:10.1016/S1385-8947(02)00025-6

(14) Fernández-Jiménez, A. y Palomo, A.: “Microstructure of alkali activated fly ash mortars: effect of the activator”, Cem. Concr. Res., nº 35 (2005), pp. 1984-1992. doi:10.1016/j.cemconres.2005.03.003

(15) Fernández-Jiménez, A. y Palomo, A.: “Characterisation of fly ashes. Potential reactivity as alkaline cements”, FUEL, nº 82 (2003), pp. 2259-2265. doi:10.1016/S0016-2361(03)00194-7

(16) Palacios, M. y Puertas, F.: “Estudio de la estabilidad de aditivos superplastificantes y reductores de la retracción en medios fuertemente alcalinos”, Mater. Construcc., vol. 54, nº 276 (2004), pp. 65-86.

(17) Neville, A. M.: Properties of Concrete, Logman Publishers, Essex, 1997.

(18) Sylla, M.H.: “Reactions in Cement Paste Due to Heat Curing” (in German), Beton, nº 38 [11] (1988), pp. 449454; ver también: Wieker, W. y Herr, R.: “On Some Problems of the Chemistry of Portland Cement”, Fur Chem., nº 29 (1989), Zeitsch, pp. 321-327.

(19) Skalny, J., Johansen, V., Thaulow, N. y Palomo, A.: “DEF as a form of sulfate attack”, Mater. Construcc. (1996), pp. 5-29.

(20) Taylor, H. F. W.: “Delayed Ettringite Formation”, Advances in Cement and Concrete (M. W. Grutzek & S.L. Sarkar, eds.), American Society of Civil Engineers, 1994; ver también: “Sulfate Reactions - Microstructural and Chemical Aspects”, Cement Technology, Ceramic Transactions, 40 (1994), pp. 61-78.

(21) Scrivener, K. L. y Taylor, H. F. W.: “Delayed Ettringite Formation: a Microstructural and Microanalytic Study”, Adv. Cem. Res., nº 5 (1993), pp. 139-146.

(22) San-José, J. T. y Frías, M.: “High performance polymer concrete”, Mater. Construcc., vol. 57, nº 286 (2007), pp. 29-39.

(23) Fernández-Jiménez, A. y Palomo, A.: “Empleo de nuevos materiales en prefabricación: hormigones de ceniza volante activada” 1er Congreso Nacional de Prefabricados, Madrid, España, 22-24 de mayo de 2002.

(24) Fernández-Jiménez, A. y Palomo, A.: “Activating fly ashes: Enlarging the concept of cementitious material”, International Symposia “Celebrating Concrete: People and Practice”, Dundee, 2003.

(25) Fernández-Jiménez, A. y Palomo, A.: “Hormigones alcalinos exentos de cemento Portland”, Revista Ingeniería de Construcción, vol. 18, nº 3 (2003), pp. 123-131.

(26) Hardjito, D., Wallah, S. E. y Rangan, B. V.: “Research into Engineering Properties of Geopolymer Concrete”, International Conference ‘Geopolymer2002 - tur potential into profit’, Melbourne, Australia, 29 de octubre de 2002.

(27) Palomo, A., Fernández-Jiménez, A. y Criado, M.: “Geopolymers: one only chemical basis, some different microstructures”, Mater. Construcc., vol. 54, nº 275 (2004), pp. 77-91.

(28) Palomo, A., Fernández-Jiménez, A., López-Hombrados, C. y Lleyda, J. L.: “Precast elements made of alkali-activated fly ash concrete”, 8th CANMET/ACI International Conference on fly ash, silica fume, slag and natural pozzolans in concrete. Las Vegas, USA (2004), 23-29 de mayo, Ed. V.M. Malhotra, ISBN: 0-87031-146-8.

(29) Fernández-Jiménez, A., Palomo, A., Sobrados, I. y Sanz, J.: “The role played by the reactive alumina content in the alkaline activation of fly ashes”, Microporous and Mesoporous Materials, 91 (2006), pp. 111-119. doi:10.1016/j.micromeso.2005.11.015

(30) Fernández-Jiménez, A., Palomo, A. y Criado, M.: “Alkali activated fly ash binders. A comparative study between sodium and potassium activators”, Mater. Construcc., vol. 56 (2006), nº 281, pp. 51-65.




How to Cite

Fernández-Jiménez, A., & Palomo, A. (2007). Factors affecting early compressive strength of alkali activated fly ash (OPC-free) concrete. Materiales De Construcción, 57(287), 7–22. https://doi.org/10.3989/mc.2007.v57.i287.53



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