Effect of thermally activated paper sludge on the mechanical properties and porosity of cement pastes


  • O. Rodríguez Instituto de Ciencias de la Construcción Eduardo Torroja (CSIC)
  • M. Frías Instituto de Ciencias de la Construcción Eduardo Torroja (CSIC)
  • M. I. Sánchez de Rojas Instituto de Ciencias de la Construcción Eduardo Torroja (CSIC)
  • R. García Universidad Autónoma de Madrid
  • R. Vigil Universidad Autónoma de Madrid




waste, paper sludge, pozzolanic addition, porosity, strength


The present article discusses the effect of paper sludge additions, calcined at 700 ºC for two hours, on cement paste pore structure and mechanical strength. Both total and capillary porosity were observed to depend on the percentage of calcined sludge added to the cementitious matrix. While a 10% addition induced values for both slightly higher than the control, adding 20% prompted the opposite result, reducing porosity values with respect to the control. Substantial refinement was observed, with a rise in pores smaller than 0.01 μm (gel pores) when the calcined sludge was added. Such refinement was greater at the higher percentage of sludge. After approximately 15 days, strength was lower in both the additioned pastes compared to the control. A high correlation (R2≥0.939) was found between total porosity and compressive strength for both percentages studied.


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(1) UNE-EN 197-1: “Cemento, Parte 1: Composición, especificaciones y criterios de conformidad de los cementos comunes” (2000).

(2) LEA’s: Chemistry of Cement and Concrete, Arnold, Great Britain (1998), p. 536.

(3) Çolak, A.: “Characteristics of pastes from a Portland cement containing different amounts of natural pozzolan”. Cem. Concr. Res., vol. 33, nº 4 (2003), pp. 585-593.

(4) Saraswathy, V.; Song, H. W.: “Corrosion performance of rice husk ash blended concrete”. Constr. Build. Mat., vol. 21, nº 8 (2007), pp. 1779-1784. doi:10.1016/j.conbuildmat.2006.05.037

(5) Hossain, K. M. A.; Lachemi, M.: “Strength, durability and micro-structural aspects of high performance volcanic ash concrete”. Cem. Concr. Res., vol. 37, nº 5 (2007), pp. 759-766. doi:10.1016/j.cemconres.2007.02.014 doi:10.1016/j.cemconres.2007.02.014

(6) Frías, M.; Sánchez de Rojas, M. I.: “Influence of the metakaolin on porous structure of matrixes based in MK/cement”. Mater. Construcc., vol. 50, nº 259 (2000), pp. 57-67.

(7) Frías, M.; Sánchez de Rojas, M. I.: “Microstructural alterations in fly ash mortars: Study on phenomena affecting particle and pore size”. Cem. Concr. Res., vol. 27, nº 4 (1997) pp. 619-628. doi:10.1016/S0008-8846(97)00026-4

(8) Frías, M.: “The effect of metakaolin on the reaction products and microporosity in blended cement pastes submitted to long hydration time and high curing temperature”. Adv. Cem. Res., vol. 18, nº 1 (2006), pp. 1-6. doi:10.1680/adcr.2006.18.1.1 doi:10.1680/adcr.2006.18.1.1

(9) Poon, C. S.; Kou, S. C.; Lam, L.: “Compressive strength, chloride diffusivity and pore structure of high performance metakaolin and silica fume concrete”. Constr. Build. Mater., vol. 20, nº 10 (2006), pp. 858-865. doi:10.1016/j.conbuildmat.2005.07.001 doi:10.1016/j.conbuildmat.2005.07.001

(10) Pera, J.; Ambroise, J.: “Pozzolanic properties of metakaolin obtained from paper sludge”, en Malhotra, V. M. (ed.): Sixth CANMET/ ACI, Conference On Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete (SP178-52), Bangkok (1998), pp. 1007-1020.

(11) Pera, J.; Amrouz, A.; “Development of highly reactive metakaolin from paper sludge”. Adv. Cem. Based Mater., vol. 7, nº 2 (1998), pp. 49-56. doi:10.1016/S1065-7355(97)00016-3

(12) Bai, J.; Chaipanich, A.; Kinuthia, J. M.; O’Farrell, M.; Sabir, B. B.; Wild, S.; Lewis, M. H.: “Compressive strength and hydration of wastepaper sludge ash-ground granulated blastfurnace slag blended pastes”. Cem. Concr. Res., vol. 33, nº 8 (2003), pp. 1189-1202. doi:10.1016/S0008-8846(03)00042-5

(13) Frías, M.; Sánchez de Rojas, M. I.; Rivera, J.: “Influence of calcining conditions on pozzolanic activity and reaction kinetics in paper sludge-calcium hydroxide mixes”, en Malhotra, V. M. (ed.): Eighth CANMET/ACI, Conference On Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete (SP-221-53), Las Vegas (2004), pp. 879-892.

(14) Banfill, P.; Frías, M.: “Rheology and conduction calorimetry of cement modified with calcined paper sludge”. Cem. Concr. Res., vol. 37, nº 2 (2007), pp. 184-190. doi:10.1016/j.cemconres.2006.11.013

(15) Vegas, I.; Frías, M.; Urreta, J.; San José, J. T.: “Obtaining a pozzolanic addition from the controlled calcination of paper mill sludge. Performance in cement matrices”. Mater. Construcc., vol. 56, nº 283 (2006), pp. 49-60. doi:10.3989/mc.2006.v56.i283.8

(16) Sabador, E.; Frías, M.; Sánchez de Rojas, M. I.; Vigil, R.; García, R.; San Jose, J. T.: “Characterization and transformation of an industrial by-product (coated paper sludge) into a pozzolanic material”. Mater. Construcc., vol. 57, nº 285 (2007), pp. 45-59. doi:10.3989/mc.2007.v57.i285.38

(17) Frías, M.; Sabador, E.; Ferreiro, S.; Sánchez de Rojas, M. I.; García, R.; Vigil, R.: “Effect of the activation of a clay-base paper industry by-product on cement matrix behaviour”. Mater. Construcc., vol. 58, nº 292 (2008), pp. 67-70. doi:10.3989/mc.2008.40607

(18) UNE-EN 196-2: “Métodos de ensayo de cemento, Parte 2: Análisis químico de cementos” (1994).

(19) Koch, A.; Steinegger, H.: “A rapid method for testing the resistence of cements to sulphate attack”. Zement-Kalk-Gips., vol. 7 (1960), pp. 317-324.

(20) Frías, M.; Sánchez de Rojas, M. I.; Rodríguez, O.; García, R.; Vigil, R.: “Characterization of calcined paper sludges as environment friently source of metakaolin for manufacture of cementing matrixes”. Adv. Cem. Res., vol. 20, n. 1 (2008), pp. 23-30. doi:10.1680/adcr.2008.20.1.23

(21) Frías, M.; Cabrera, J.: “Pore size distribution and degree of hydration of metakaolin cement pastes”. Cem. Concr. Res., vol. 30, nº 4 (2000), pp. 561-569. doi:10.1016/S0008-8846(00)00203-9

(22) Khabit, J. M.; Wild, S.: “Pore size distribution of MK paste”. Cem. Concr. Res., vol. 26, nº 10 (1996), pp. 1545-1553.

(23) Hasselman, D. P. H.: “Relation between effects of porosity on strength and Young’s modulus of elasticity of polycrystalline materials”. J. Am. Ceram. Soc., vol. 46, nº 1 (1963), pp. 564-565. doi:10.1111/j.1151-2916.1963.tb14615.x




How to Cite

Rodríguez, O., Frías, M., Sánchez de Rojas, M. I., García, R., & Vigil, R. (2009). Effect of thermally activated paper sludge on the mechanical properties and porosity of cement pastes. Materiales De Construcción, 59(294), 41-52. https://doi.org/10.3989/mc.2009.41007



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