Architectural Ceramics: Difference between revisions

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== Introduction ==
== Introduction ==
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== Decay Pattern of Architectural Ceramics==
== Decay Pattern of Architectural Ceramics==


'''Ziegelschäden'''
'''Deterioration of Brickwork'''


Salt-induced damage to bricks are common.
Salt-induced damage to bricks is common.


Damage to bricks can look like this:
Damage to bricks can appear as follows:




'''Glazed Architectural Ceramics'''
'''Glazed Architectural Ceramics'''


The glaze of a glazed building ceramics prevents both the transport of moisture and salts. Often   however glaze is crackled, which allows a capillary moisture transport. The Craquelée particularly clear shows an existing salt load, which consequently often leads to the spalling of the glazes.
The glaze on building ceramics prevents the transport of moisture and salts. Often however, the glaze is split into a fine network of cracks (craquele), allowing the moisture transport through capillary action.  
In the fissures of the craquele, salt contamination can be seen particularly well and often this damage leads to the spalling of the glazes.
 


Some examples of salt-contaminated glazed building ceramics are shown here.
Some examples of salt-contaminated glazed building ceramics are shown here.
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=== Flaking ===
=== Flaking ===


<gallery perrow="3" heights="200px" widths="250px" caption="Decay pattern on a brick of the St.Jakobi church in Perleberg">
<gallery perrow="3" heights="200px" widths="250px" caption="Decay pattern on a brick of the St. Jakobi Church in Perleberg">


Image:Perleberg 14.04.2003 (50)-Ausschnitt.jpg|Figure 1: The damaged brick shows a scaly surface, which was caused by crystallizing salts.  
Image:Perleberg 14.04.2003 (50)-Ausschnitt.jpg|Figure 1: The scaling surface of a damaged brick, caused by crystallizing salts.  
Image:Per_270603_5-13_14.jpg|Figure 2: Photo of a thin section in polarized light. The grey parallel crystals are gypsum.
Image:Per_270603_5-13_14.jpg|Figure 2: Photo of a thin section in polarized light. The gray parallel crystals are gypsum.
Image:Per 270603 5-13 15.jpg|Figure 3: Photomicrograph as Fig 2 but with crossed polarisers. It is clearly seen that the plaster is both responsible for the damage and on the other hand, he acts in this case as a kind of glue that holds together the broken brick pieces. With the removal of the original plaster the brick material would be lost.</gallery>
Image:Per 270603 5-13 15.jpg|Figure 3: Photo micrograph as Fig 2 with crossed polarizers. It is clearly visible that, on the one hand gypsum is causing the damage to the brick, but on the other hand it acts like an adhesive/ cement, holding the flaking pieces in place. With the removal of the gypsum the original substance of the brick would be lost.</gallery>


===Back Weathering ===
===Weathering ===


<gallery perrow="3" heights="200px" widths="250px" caption="Damage to a building in Lüneburg">
<gallery perrow="3" heights="200px" widths="250px" caption="Damage to a building in Lüneburg">


Image:Lueneburg-AmSande1 1.jpg|Figure  4: Salts are damaging a shaped bloc
Image:Lueneburg-AmSande1 1.jpg|Figure  4: Salts causing damage to a molded brick
Image:Lueneburg-AmSande1 2.jpg|Figure  5: Salt damage under a coating
Image:Lueneburg-AmSande1 2.jpg|Figure  5: Salt action under a coat of paint, scaling and disintegration of the brick


</gallery>
</gallery>
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<gallery perrow="3" heights="200px" widths="250px" caption="Efflorescences on Architectural Ceramics">
<gallery perrow="3" heights="200px" widths="250px" caption="Efflorescences on Architectural Ceramics">


Image: Salzwedel 17012007 (145).jpg|Figure  6: Salt on a floor plate
Image: Salzwedel 17012007 (145).jpg|Figure  6: Salt efflorescence on a flagstone
Image: Pilsum salz auf Ziegelsaeule.jpg|Figure 7: Carbonate salts form a crust on a pillar. Cause in this case were  a injection with cement slurry
Image: Pilsum salz auf Ziegelsaeule.jpg|Figure 7: Encrustations on a pillar formed by carbonate salts and caused by the leaching of cement slurry injections.
Image:Lueneburg-AmSande1 3.jpg|Figure 8: Crystallizing salts make the crackles on a glazed tile visible. With time, the salts will damage the glaze.
Image:Lueneburg-AmSande1 3.jpg|Figure 8: Crystallizing salts accentuate the craquele on a glazed tile. Gradually, the salts will damage the glaze.
</gallery>
</gallery>


Revision as of 13:46, 11 October 2011

<bibimport/>
Author: Hans-Jürgen Schwarz
Back to Decay Pattern



Abstract[edit]

Typical damage patterns are presented and explained.


Decay Pattern of Architectural Ceramics[edit]

Deterioration of Brickwork

Salt-induced damage to bricks is common.

Damage to bricks can appear as follows:


Glazed Architectural Ceramics

The glaze on building ceramics prevents the transport of moisture and salts. Often however, the glaze is split into a fine network of cracks (craquele), allowing the moisture transport through capillary action. In the fissures of the craquele, salt contamination can be seen particularly well and often this damage leads to the spalling of the glazes.


Some examples of salt-contaminated glazed building ceramics are shown here.

Flaking[edit]

  • Decay pattern on a brick of the St. Jakobi Church in Perleberg
  • Figure 1: The scaling surface of a damaged brick, caused by crystallizing salts.

    Figure 1: The scaling surface of a damaged brick, caused by crystallizing salts.

  • Figure 2: Photo of a thin section in polarized light. The gray parallel crystals are gypsum.

    Figure 2: Photo of a thin section in polarized light. The gray parallel crystals are gypsum.

  • Figure 3: Photo micrograph as Fig 2 with crossed polarizers. It is clearly visible that, on the one hand gypsum is causing the damage to the brick, but on the other hand it acts like an adhesive/ cement, holding the flaking pieces in place. With the removal of the gypsum the original substance of the brick would be lost.

    Figure 3: Photo micrograph as Fig 2 with crossed polarizers. It is clearly visible that, on the one hand gypsum is causing the damage to the brick, but on the other hand it acts like an adhesive/ cement, holding the flaking pieces in place. With the removal of the gypsum the original substance of the brick would be lost.

Weathering[edit]

  • Damage to a building in Lüneburg
  • Figure 4: Salts causing damage to a molded brick

    Figure 4: Salts causing damage to a molded brick

  • Figure 5: Salt action under a coat of paint, scaling and disintegration of the brick

    Figure 5: Salt action under a coat of paint, scaling and disintegration of the brick

Efflorescences[edit]

  • Efflorescences on Architectural Ceramics
  • Figure 6: Salt efflorescence on a flagstone

    Figure 6: Salt efflorescence on a flagstone

  • Figure 7: Encrustations on a pillar formed by carbonate salts and caused by the leaching of cement slurry injections.

    Figure 7: Encrustations on a pillar formed by carbonate salts and caused by the leaching of cement slurry injections.

  • Figure 8: Crystallizing salts accentuate the craquele on a glazed tile. Gradually, the salts will damage the glaze.

    Figure 8: Crystallizing salts accentuate the craquele on a glazed tile. Gradually, the salts will damage the glaze.

Literature[edit]

crystallization of a dissolved salt

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