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Crystallization force of sodium chloride
Koudelková, Veronika ; Wolf, Benjamin
Soluble salts are one of the most deteriorating factor causing damage of historical building materials due to generation of crystallization pressure inside pore space. Direct measurement of crystallization force is quite challenging, hence we developed at our institute a novel device able to detect the force of growing crystal. The device is based on the monitoring of force developed with upper microscopic glass on the growing crystal to maintain constant position. The crystal could generate force because of the existence of thin liquid layer of solution between both surfaces come into contact. The driving force for the subsequent growth of crystal against obstacle is supersaturation, which is mainly induced by evaporation of the salt solution. In this experiment, the crystal of sodium chloride generated force 16.8 mN and the corresponding crystallization pressure was equal to the value 0.48 MPa.
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Chemical and microscopic analysis of external plaster, Petschek villa, V sadech 2, Prague 6
Slížková, Zuzana ; Viani, Alberto ; Koudelková, Veronika ; Frankeová, Dita ; Hauková, Petra
The aim of this work was to analyze mortar from Petschek villa, XRD and SEM-EDX analyzes have been proposed, which results in the characterization of aggregate and mortar binders. The analyses proved gypsum plaster with surface paint.
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