Crystallization from Sodium Sulphate Solution Confined in Red Clay Brick during Temperature Decrease

Abstract:

Water with dissolved contaminations is a frequent problem faced in porous building materials such as masonry, or cement-based composites. It regards both contemporary constructions, and those belonging to the cultural heritage. Among soluble salts, sodium sulfate is recognized as one of the most dangerous one. Since crystals of Na₂SO₄ can occur in the variety of forms, its crystallization in pores of a building material is a challenging and not fully recognized issue. The main object of the presented research is to identify the consecutive phase transitions occurring within red clay brick containing sodium sulphate solution during cooling. The first stage of an experimental investigation was performed by means of mercury intrusion porosimetry to verify whether cyclic crystallization has a damaging effect on material microstructure. In the second step of experimental analysis differential scanning calorimetry was applied. The technique was used to monitor the crystallization of sodium sulphate confined in samples during repeating cooling-heating cycles covering temperature range from -20°C to 40°C. It was observed that during primary crystallization, sodium sulfate heptahydrate is the first precipitating phase and the transition begins far below its equilibrium temperature. Subsequently, the heptahydrate transforms into mirabilite, which probably induced rapid ice crystallization. Nevertheless, if decahydrate nuclei are provided in pore solution, sodium sulphate precipitates directly as mirabilite with no heptahydrate formation. Such a pattern is observed for both analysed solution concentration, i.e. 25% and 30%.

• Periodical: Key Engineering Materials (Volume 916)
• Pages: 123-129
• DOI: https://doi.org/10.4028/p-14k7oj
• Online since: April 2022
• Authors: Dalia Bednarska*, Marcin Koniorczyk
• Keywords: Building Materials Deterioration, Red Clay Brick, Salt Crystallization, Sodium Sulphate

References

[1] C. Rodriguez-Navarro, E. Doehne, and E. Sebastian, How does sodium sulfate crystallize? Implications for the decay and testing of building materials,, Cement and concrete research, vol. 30, no. 10, pp.1527-1534, (2000).

DOI: 10.1016/s0008-8846(00)00381-1

[2] R. Espinosa, L. Franke, and G. Deckelmann, Model for the mechanical stress due to the salt crystallization in porous materials,, Construction and Building Materials, vol. 22, no. 7, pp.1350-1367, (2008).

DOI: 10.1016/j.conbuildmat.2007.04.013

[3] A. Hamilton, C. Hall, and L. Pel, Sodium sulfate heptahydrate: direct observation of crystallization in a porous material,, Journal of Physics D: Applied Physics, vol. 41, no. 21, p.212002, (2008).

DOI: 10.1088/0022-3727/41/21/212002

[4] R. M. E. Marzal and G. W. Scherer, Crystallization of sodium sulfate salts in limestone,, Environmental Geology, vol. 56, no. 3, pp.605-621, (2008).

DOI: 10.1007/s00254-008-1441-7

[5] M. Steiger and S. Asmussen, Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress,, Geochimica et Cosmochimica Acta, vol. 72, no. 17, pp.4291-4306, (2008).

DOI: 10.1016/j.gca.2008.05.053

[6] E. W. Washburn, The dynamics of capillary flow,, Physical review, vol. 17, no. 3, p.273, (1921).

[7] G. Höhne, W. F. Hemminger, and H.-J. Flammersheim, Differential scanning calorimetry. Springer Science & Business Media, (2013).

[8] C. Michaelsen and M. Dahms, On the determination of nucleation and growth kinetics by calorimetry,, Thermochimica acta, vol. 288, no. 1-2, pp.9-27, (1996).

DOI: 10.1016/s0040-6031(96)03039-0

[9] P. Marliacy, R. Solimando, M. Bouroukba, and L. Schuffenecker, Thermodynamics of crystallization of sodium sulfate decahydrate in H2O–NaCl–Na2SO4: application to Na2SO4· 10H2O-based latent heat storage materials,, Thermochimica acta, vol. 344, no. 1-2, pp.85-94, (2000).

DOI: 10.1016/s0040-6031(99)00331-7

[10] H. Hartley, B. M. Jones, and G. A. Hutchinson, LXXV.—The spontaneous crystallisation of sodium sulphate solutions,, Journal of the Chemical Society, Transactions, vol. 93, pp.825-833, (1908).

DOI: 10.1039/ct9089300825