Magnesium sulfate salts and historic building materials: experimental simulation of limestone flaking by relative humidity cycling and crystallization of salts

Authors

  • P. Lopez-Arce The Getty Conservation Institute, Los Angeles
  • E. Doehne The Getty Conservation Institute, Los Angeles
  • W. Martin English Heritage, London
  • S. Pinchin English Heritage, London

DOI:

https://doi.org/10.3989/mc.2008.v58.i289-290.77

Keywords:

Magnesium sulfate, Limestone, flaking, salt decay, humidity cycling

Abstract


Magnesium sulfate salts often result from the combination of incompatible construction materials, such as stone or mortar with high magnesium content and sulfates from adjacent mortars or polluted air. When combined with a source of moisture, these materials react to form soluble salts, often leading to significant damage by flaking of the stone, as the magnesium sulfate responds to fluctuating environmental conditions. Several laboratory experiments were performed to reproduce surface flaking on different types of limestone from Spain and the UK to evaluate the effects of humidity cycling on the damage of stone by salt crystallization. The two salt solutions used for the experiments were a single salt of magnesium sulfate and a mixture of magnesium sulfate, calcium sulfate and sodium chloride, a typical salt mixture found in damaged stone at the site of Howden Minster (UK). A climate chamber with precise and programmable temperature and humidity control was used to test the hypothesis that salt damage in the stone can be readily caused by humidity fluctuations. Damage was monitored using Linear Variable Differential Transformer (LVDT), which measure transducers displacement by dimensional change on the order of microns. In addition, Ion Chromatography, Environmental Scanning Electron Microscopy with energy dispersive X-ray spectroscopy (ESEM-EDX) and X-ray Diffraction analyses (XRD) were also carried out to analyze salt behavior. Damage by flaking took place in two types of magnesian limestone cubes impregnated with the salt mixture, from Cadeby quarry and York Minster, apparently by deliquescent salts of low equilibrium relative humidity (RHeq), while the rest of the samples developed a salt crust over the surface, but no damage was observed in the stone. It is important to verify hypotheses developed from field observations with laboratory experiments. By combining both field and laboratory data, a clearer understanding the different mechanisms of decay and associated weathering types under different environmental conditions can be obtained.

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References

(1) Winkler, E.M.: “Egyptian Obelisks (Cleopatra’s Needles) of New York City and London-Environmental History and weathering”, Internationale Zeitschrift fur Bauinstandsetzen, nº6 (1996), pp. 519-530.

(2) Alaimo, R., Di Franco, L., Gagliardo Briuccia, V., Giarrusso, R., Montana, G.: “Plasters of the historical buildings of Palermo (Sicily): Raw Materials, causes and mechanisms of decay”. IV Int. Sym. on the Conservation of Monuments in the Mediterranean Basin. 53-64, Rhodes, 1997.

(3) El-Metwally, A.A., Ramadan, A.B.: “The role of air pollutants and sewage waste in acceleration of degradation of the Islamic cultural heritage of Cairo”, Comparative Risk Assessment and Environmental Decision Making. pp. 367-374. Kluwer Academic Publishers, Dordrecht, 2003.

(4) Livingstone, R.A.: “Influence of evaporite minerals on gypsum crusts and alveolar weathering”. III Int. Sym. on the Conservation of Monuments in the Mediterranean Basin. 101-107, Venezia, 1994.

(5) Fitzner, B., Heinrichs, K.: “Damage diagnosis at monuments carved from bedrocks in Petra, Jordan”. III Int. Sym. on the Conservation of Monuments in the Mediterranean Basin. 663-672, Venezia, 1994.

(6) Gómez-Heras, M., Benavente, D., Alvarez De Buergo, M., Fort R.: “Soluble salt minerals from pigeon droppings as potential contributors to the decay of stone based Cultural Heritage”, Eur. J. Mineral., nº16 (2004), pp. 505-509. doi:10.1127/0935-1221/2004/0016-0505

(7) Laue, S., Böhm, C.B., Jeannette, D.: “Salt weathering and. porosity—examples from the crypt of St. Maria im kapitol, Cologne”. 8th Int. Cong. on Deterioration and Conservation of Stone. 513-522, Berlin, 1996.

(8) Cooke, R.U.: “Salt Weathering and the Urban Water Table in Deserts”, Rock Weathering and Landform Evolution, p.519, John Wiley & Sons, Chichester, 1994.

(9) Linnow, K., Zeunert, A., Steiger, M.: “Investigation of Sodium Sulfate Phase Transitions in a Porous Material Using Humidity and Temperature-Controlled X-ray Diffraction”, Anal. Chem. nº78 (2006), pp. 4683-4689. doi:10.1021/ac0603936

(10) Charola, A.E., Lewin, S.Z.: “Efflorescences on building stones—SEM in the characterization and elucidation of mechanisms of formation”, Scan. Electr. Microsc. nº1 (1979), pp. 379-386.

(11) Cooke, R.U., Gibbs, G.B.: “Crumbling Heritage? Studies of stone weathering in polluted atmospheres”, p.68, National Power plc and PowerGen plc, Swindon, 1993.

(12) Benavente, D., Garcia del Cura, M.A., Garcia-Guinea, J., Sanchez-Moral, S., Ordoñez, S.: “Role of pore structure in salt crystallisation in unsaturated porous stones”, J. Cryst. Growth., nº260 (2004), pp. 532-544. doi:10.1016/j.jcrysgro.2003.09.004

(13) Cultrone, G., Russo, L. G., Calabrò, C., Uroševič1, M., Pezzino A.: “Influence of pore system characteristics on limestone vulnerability: a laboratory study”, Environ. Geol., ISSN 0943-0105 (Print) 1432-0495 (Online) (2007).

(14) Ruiz-Agudo, E., Mees, F., Jacobs, P., Rodriguez-Navarro, C.: “The role of saline solution properties on porous limestone salt weathering by magnesium and sodium sulfates. Environ. Geol, Vol. 52, nº.2 (2007), pp. 269-281. doi:10.1007/s00254-006-0476-x

(15) Sherman, L.A., Barak, P.: “The solubility and dissolution kinetics of dolomite [CaMg(CO3)2] in Ca-Mg-HCO3/CO3 solutions at 25°C and 0.1 MPa carbon dioxide”, Soil Sci. Soc. Am. J., nº64 (2000), pp. 1959-1968.

(16) Caner, E.N., Demirci, S. A., Turkmenoglu, G.: “Deterioration of dolomite by soluble salts in Divrigi Mosque-Turkey”. 5th Int. Cong. On Deterioration and Conservation of Stone. 299-305, Lausanne, 1985.

(17) Blanco Varela, M.T., Menéndez, E., Hoyos, M.: “Study of surface decay of the marbles and serpentine from the Descalzas Reales Convent at Madrid”. II Int. Sym. on the Conservation of Monuments in the Mediterranean Basin. 167-175, Geneve, 1991.

(18) Storemyr, P.: “A study on the weathering of Norwegian Greenschist”. 8th Int. Cong. on Deterioration and Conservation of Stone. 489-495, Berlin, 1996.

(19) Schaffer, R.J.: “The weathering of Natural Building Stones”, p.149, His Majestys Stationery Office, London, 1932.

(20) Laurie, A.P.: “Stone decay and the preservation of buildings”, J. Soc. Chem. Ind., nº 27 (1925), pp. 86-92.

(21) Martin, L., Bello, M.A., Martin, A.: “The efflorescences of The Cathedral of Almería”. 7th Int. Cong. On Deterioration and Conservation of Stone. 869-873, Lisbon, 1992.

(22) Carretero, M.I., Galán, E.: “Marine spray and urban pollution as the main factors of stone damage in the cathedral of Málaga (Spain)”. 8th Int. Cong. On Deterioration and Conservation of Stone. 311-324, Berlin, 1996.

(23) Fort, R., Varas M.J., Pérez-Monserrat, E., Vázquez-Calvo, C.: “Hexahidrita-epsomita en el deterioro de piedra dolomítica del patrimonio arquitectónico - Hexahydrite-epsomite on dolomitic stone decay in the architectonic heritage”. XXV Reunión de la Sociedad española de Mineralogía. 77-79, Alicante, 2005.

(24) González Limón, T., Álvarez de Buergo Ballester, M.: “Los revocos de cal de las fachadas de la plaza de la Corredera de Cordoba – The lime renderings from plaza de la Corredera, Cordoba”, Mater. Construcc., Vol. 52, nº267 (2002), pp. 19-30.

(25) Bourges, A., Doehne, E., Carson, D., Hanna, S., Martin, W.: “Physical-mechanical properties and decay mechanisms of magnesian limestones of northern England used for stone replacement”. Work in progress (2007).

(26) Lott, G.K., Richardson, C.: “Yorkshire stone for building the Houses of Parliament (1839-c.1852)”. Proceed. of the Yorkshire Geological Society, 51:265-272, London,1997.

(27) Fort, R., Bernabeu, A., Del Cura, M.A., López de Azcona, M.C., Ordoñez, S., Mingarro, F.: “La piedra de Novelda: una roca muy utilizada en el patrimonio arquitectónico - Novelda Stone: widely used within the spanish architectural heritage”, Mater. Construcc., Vol. 52, nº266 (2002), pp. 19-32.

(28) Charola, A.E.: “Salts in the deterioration of porous materials: an overview”, J. Am. Inst. Conserv., Vol. 39, nº3 (2000), pp. 327-343. doi:10.2307/3179977

(29) Sanjeev, T., Lal Gauri, K., Suhan, L., Cobourn, W.G.: “Kinetic study of SO2 reaction with dolomite”, Environ. Sci. Technol., nº25 (1991), pp. 2071-2075.

(30) Arnold, A., Zehnder, K.: “Decay of stony materials by salts on humid atmosphere”. 6th Int. Cong. On Deterioration and Conservation of Stone. 138-148, Torun, 1988.

(31) Arnold, A., Zehnder, K.: “Salt weathering on monuments”. I Int. Sym. on the Conservation of Monuments in the Mediterranean Basin. 31–58, Bari, 1989.

(32) Juling, H., Kirchner, D., Bruggerhoff, S., Linnow, K., Steiger, M., El Jarad, A., Gulker, G.: “Salt damage of porous materials: a combined theoretical and experimental approach”. 10th Int. Cong. On Deterioration and Conservation of Stone. 187-194, Stockholm, 2004.

(33) Phadnis, A.B., Deshpande, V.V.: “On the dehydration of MgSO4⋅7H2O”, Thermochim. Acta, nº 43 (1981), pp. 249-250.

(34) Binda, L., Baronio, G., Charola, A.E.: "Deterioration of porous materials due to salt crystallization under different thermohygrometric conditions. I. Brick”. 5th Int. Cong. On Deterioration and Conservation of Stone. 279-287, Lausanne, 1985.

(35) López-Arce, P., Doehne E.: “Kinetics of sodium sulfate efflorecence as observed by humidity cycling with ESEM”. Proceed. Int. Conf. on Heritage, Weathering and Conservation. 285-291, Madrid, 2006.

(36) Rodriguez-Navarro, C., Doehne E.: "Salt weathering: influence of evaporation rate, supersaturation and crystallization pattern." Earth Surf. Proc. Land. Vol. 24, nº.3 (1999), pp. 191-209. doi:10.1002/(SICI)1096-9837(199903)24:3<191::AID-ESP942>3.0.CO;2-G

(37) Doehne, E., Selwitz, C., Carson D.: “The damage mechanism of sodium sulfate in porous stone”. Proceed. of the SALTeXPERT Meeting. 27-146, Prague, 2006.

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Published

2008-06-30

How to Cite

Lopez-Arce, P., Doehne, E., Martin, W., & Pinchin, S. (2008). Magnesium sulfate salts and historic building materials: experimental simulation of limestone flaking by relative humidity cycling and crystallization of salts. Materiales De Construcción, 58(289-290), 125–142. https://doi.org/10.3989/mc.2008.v58.i289-290.77

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