This study investigates the action of environmentally-friendly functionalized polycarboxylates as organic crystallization modifiers on salts in Globigerina Limestone. These compounds are non-toxic, water/alcohol soluble and easy to apply, thereby enabling their use in accordance with the volatile organic compounds emission control and safety during the conservation works. Generally successful applications of these chemicals to limit damage have been reported, under controlled environments, and are materials currently being researched for limiting salt damage on this typical building stone. The main aim of the research has been to observe modifications to salt crystal growth induced in two varieties of Globigerina Limestone by the application of crystallization modifiers. This was done with a focus on the potential of such compounds to control, and therefore, limit damage. These systematic studies on this locally unexplored territory have primarily focused on the damaging action of sodium sulphate, as one of the most damaging salt types, but also on sodium chloride and binary mixtures thereof. Crystallization experiments in bulk solution, but more importantly evaporation tests under both controlled and uncontrolled laboratory conditions have been performed. In this paper, the results obtained of this still experimental method of limiting salt damage on local stone shall be discussed, in the context of former trials on this type of stone and the fact that results are still under investigation. Any effect on deterioration and changes to its crystallization habit of contaminant salts, following the application of salt crystallization modifying treatments on the stone systems, have been visually and microscopically observed. A discussion for founding a classification of damage induced according to environmental conditions, crystalline structure and substrate type according to contaminant and treatment has been postulated.
Investigating a method to limit salt damage in Globigerina Limestone, a soft porous stone used widely in historic buildings
MARROCCHI, Assunta;
2014
Abstract
This study investigates the action of environmentally-friendly functionalized polycarboxylates as organic crystallization modifiers on salts in Globigerina Limestone. These compounds are non-toxic, water/alcohol soluble and easy to apply, thereby enabling their use in accordance with the volatile organic compounds emission control and safety during the conservation works. Generally successful applications of these chemicals to limit damage have been reported, under controlled environments, and are materials currently being researched for limiting salt damage on this typical building stone. The main aim of the research has been to observe modifications to salt crystal growth induced in two varieties of Globigerina Limestone by the application of crystallization modifiers. This was done with a focus on the potential of such compounds to control, and therefore, limit damage. These systematic studies on this locally unexplored territory have primarily focused on the damaging action of sodium sulphate, as one of the most damaging salt types, but also on sodium chloride and binary mixtures thereof. Crystallization experiments in bulk solution, but more importantly evaporation tests under both controlled and uncontrolled laboratory conditions have been performed. In this paper, the results obtained of this still experimental method of limiting salt damage on local stone shall be discussed, in the context of former trials on this type of stone and the fact that results are still under investigation. Any effect on deterioration and changes to its crystallization habit of contaminant salts, following the application of salt crystallization modifying treatments on the stone systems, have been visually and microscopically observed. A discussion for founding a classification of damage induced according to environmental conditions, crystalline structure and substrate type according to contaminant and treatment has been postulated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
