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SALT CRUST
SALT CRUST

Sample

Nostra Senyora del Remei Chapel. Monastery of Aviganya. LLeida. Spain.


Pathology Causes

Rising damp of water contaminated by debris and fertilizers that imparts potassium nitrate and other alkalis to the stone. Another less important source of salts comes from the existing tombs under the pavement.

Visual Image

Author: CETEC-patrimoni

Description: Rising damp from the floor (the church is built on a geological structure that favours water and moisture retention).


Image detail / macro

SALT CRUST
Author: CETEC-patrimoni
Magnification: x20
Description: Sub-rounded and amoeboid crystal habits. These habits indicate that salts are very hygroscopic and have grown into a very wet wall.

Microscope Image

SALT CRUST
SALT CRUST
Author: CETEC-patrimoni
Magnification: Figure 1. x750. Figure 2. x1000 - SEM-BSEI
Description:
Sub-rounded and amoeboid crystal habits indicate that the salts have grown in a very wet wall in direct contact with moisture. Their tendency to cluster in nodules indicates long repeated cycles of crystallization, mainly linked to seasonal changes and different periods of rain.

Associated Pathologies

Flaking.

Sanding.

Blistering.

Alveolization.


Other Tests

DRX

Observations

Potassium nitrates and other alkali salts (niter) and magnesium sulphates (hexaedrite).

Bibliography

ARNOLD, A. & KUENG, A., (1985), Cristallization and Habits of Salt Efflorescences on Walls. Part I, Methods of Investigation and Habits. Vth hitemational Congress on Deterioration and Conservation of Stone. Lausanne. pp. 255-268.
 
ARNOLD, A. &  ZEHNDER, K., (1985), Cristallization and Habits of Salt Efflorescences on Walls. Part.II, Conditions of Cristallization. Vth International Congress on Deterioration and Conservation of Stone, Lausanne. pp. 269-277.
 
CHAROLA, A. E. Salts in deterioration of porous material: an overwiew. JAIC, 39.2000. pp. 327-343.

Author

Jose Luis Prada Pérez. prada43@wanadoo.es

Geologo


Institution or Company

ESCRBCC


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