TY - JOUR
T1 - Crystallization of sodium sulfate salts in limestone
AU - Espinosa Marzal, Rosa M.
AU - Scherer, George W.
N1 - Funding Information:
Acknowledgments The authors thank the financial support by the Deutsche Forschungsgemeinschaft and by the Getty Conservation Institute.
PY - 2008/12
Y1 - 2008/12
N2 - Crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage to stone and masonry. In this work, the crystallization of sodium sulfate salts in Cordova Cream and Indiana limestones is investigated using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The DSC experiments indicate that sodium heptahydrate always precipitates prior to the decahydrate (mirabilite), at a temperature between 15 and 7°C in the selected stones. The threshold supersaturation for the nucleation of heptahydrate is less than 2. In constrast, mirabilite precipitates close to or below 0°C and its crystallization pattern is completely different: precipitation takes place abruptly when the threshold supersaturation is reached, which is greater than 7. Indeed, the DSC and the DMA experiments reveal the rare nature of the nucleation of mirabilite for the investigated stones. The crystallization pressure exerted by heptahydrate does not cause damage under the conditions of the cooling experiments. In contrast, mirabilite exerts a very high crystallization pressure on the pore wall causing damage of the stone; moreover, the transient stress can remain for a long period of time since the relaxation process is slow.
AB - Crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage to stone and masonry. In this work, the crystallization of sodium sulfate salts in Cordova Cream and Indiana limestones is investigated using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The DSC experiments indicate that sodium heptahydrate always precipitates prior to the decahydrate (mirabilite), at a temperature between 15 and 7°C in the selected stones. The threshold supersaturation for the nucleation of heptahydrate is less than 2. In constrast, mirabilite precipitates close to or below 0°C and its crystallization pattern is completely different: precipitation takes place abruptly when the threshold supersaturation is reached, which is greater than 7. Indeed, the DSC and the DMA experiments reveal the rare nature of the nucleation of mirabilite for the investigated stones. The crystallization pressure exerted by heptahydrate does not cause damage under the conditions of the cooling experiments. In contrast, mirabilite exerts a very high crystallization pressure on the pore wall causing damage of the stone; moreover, the transient stress can remain for a long period of time since the relaxation process is slow.
KW - Crystal growth
KW - Crystallization pressure
KW - Nucleation
KW - Sodium sulfate
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U2 - 10.1007/s00254-008-1441-7
DO - 10.1007/s00254-008-1441-7
M3 - Article
AN - SCOPUS:55849137977
SN - 0943-0105
VL - 56
SP - 605
EP - 621
JO - Environmental Geology
JF - Environmental Geology
IS - 3-4
ER -