Research on the Relationship between Thermal Conductivity and Porosity during Carbonation of Cement Materials

Abstract:

The objective of this work was to examine the relationships that may exist between porosity and thermal conductivity with particular reference to normalized cement mortar which is most commonly found in civil engineering. Samples were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO₂ concentration. We investigated the evolution of the total porosity measured by hydrostatic weighing and of the thermal properties measured by Hotdisk method. This experimental campaign allowed relating the total porosity and the thermal conductivity before and during carbonation. These results can be used for further studies which can propose models predicting the thermal conductivity if changes in porosity are known. Moreover, the results indicated that the thermal conductivity of a cement material is directly related to the density and inversely related to porosity. Finally, this study showed that a characteristic coefficient can be deduced for two states of material: non-carbonated and carbonated. This coefficient is therefore proper to a specific material and can be used not only for modeling the relationship between porosity and thermal properties but also for other microstructural studies of cement materials.

• Periodical: Advanced Materials Research (Volumes 1065-1069)
• Pages: 1838-1841
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1065-1069.1838
• Online since: December 2014
• Authors: Son Tung Pham*
• Keywords: Carbonation, Cement Mortar, Porosity, Thermal Properties

References

[1] M. Thiery, Modelling of atmospheric carbonation of cement based materials considering the kinetic effects and modifications of the microstructure, Thèse de doctorat, L'école nationale des ponts et chausses, (2005).

[2] V. Baroghel-Bouny, Conception des bétons pour une durée de vie donnée des ouvrages – Maîtrise de la durabilité vis-à-vis de la corrosion des armatures et de l'alcali réaction – Etat de l'art et guide pour la mise en œuvre d'une approche performantielle sur la base d'indicateurs de durabilité, Association française de Génie Civil, (2004).

DOI: 10.3166/ejece.13.9-19

[3] Détermination de la masse volumique apparente et de la porosité accessible à l'eau, In J.O. Ollivier, éditeur : Durabilité des béton, Méthodes recommandées pour la mesure des grandeurs associées à la durabilité, Laboratoires des Matériaux et Durabilité des Constructions (L.M.D. C), 1997, pp.121-124.

DOI: 10.1051/mattech/2023006

[4] Y. Jannot, Théorie et pratique de la métrologie thermique, Laboratoire d'Energétique et de Mécanique Théorique et Appliquée, Octobre (2011).

[5] A.M. Neville, Properties of concrete, London: Ed. Longman scientific and technical, (1990).