Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A method to recreate historic mortars applied at Norr­landa church on the island of Gotland, Sweden
Department of Chemical and Biological Engineering, Environmental Inorganic Chemistry, Chalmers University of Technology.ORCID iD: 0000-0002-2994-1766
Department of Chemical and Biological Engineering, Environmental Inorganic Chemistry, Chalmers University of Technology.
2008 (English)Conference paper, Published paper (Refereed)
Abstract [en]

In this work, scanning electron microscopy analysis of lime slaked in different ways and analysis of thin section limeputty and mortar specimens by light microscopy was combined with practical tests and field studies in order to evaluatethe impact of the slaking technique on the properties of the lime putty, and also the structure of the fresh and carbonatedmortar. The lime slaking methods studied were wet slaking and earth slaking. These techniques give lime putties withvery different consistency and workability. The aim of this work was to use microscopy techniques to explain thesedifferences in properties and to investigate if it is possible to use these analytical methods to recognize the lime slakingtechnique used in a historical lime mortar.The results obtained by electron microscopy show significant differences in structure between the lime puttiesstudied. The earth slaked lime consists of relatively large particles that are packed in a porous system as compared to thewet slaked lime with very small particles closely packed in a dense structure. After storing, the wet slaked lime gives aputty, that has a dense and clearly defined stratified structure, whereas the earth slaked lime is porous and has nostratification. The earth slaked lime is tixotropic and has a light, smooth consistency reminding of well whipped creamcompared to the wet slaked lime that has a strong orientation and a rather stiff consistency reminding more of pudding.Microscopy investigations of thin section mortar specimens showed how the lime affects the mortar concerninghomogeneity, density, pore structure and crack patterns.

Place, publisher, year, edition, pages
2008.
Keyword [en]
lime putty/lime mortar/slaking technique/Ca(OH)2/SEM/thin section/craftsmanship/earth slaked lime
National Category
Other Natural Sciences
Research subject
Conservation (HGO)
Identifiers
URN: urn:nbn:se:uu:diva-220081OAI: oai:DiVA.org:uu-220081DiVA: diva2:704008
Conference
Proceedings of Historical Mortars Conference HMC-2008, Lisbon, Portugal 2008
Funder
Knowledge Foundation
Available from: 2014-03-10 Created: 2014-03-10 Last updated: 2014-04-16Bibliographically approved
In thesis
1. Traditional lime mortar and plaster : Reconstruction with emphasis on durability
Open this publication in new window or tab >>Traditional lime mortar and plaster : Reconstruction with emphasis on durability
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Lime mortar and plaster have been investigated with the aim to improve the knowledge on how to make them as durable as before the cement technology was developed. The background was the durability problems experienced for newly produced lime plaster on the medieval churches on the island of Gotland, Sweden. In some cases the new lime plaster façades showed severe frost damages after only one winter. Although the lime was burnt and produced according to old local traditions, the lime mortar was still mixed and worked onaccording to methods developed for lime-cement mortar. This often led to a very porous lime plaster with a lime shell in the surface and such a plaster has been shown to be sensitive to frost expansion. Field studies were combined with laboratory studies of thin section specimens. Optical microscopy and scanning electron microscopy have been important analytical methods showing the porosity and the structure of the binder and aggregate materials. The investigations have been carried out on both historic and on newly made reference mortar and plaster. The field studies were carried out mainly on Gotland, using local materials. The influence of the raw materials, i.e. lime, aggregate and blending ratio was investigated. The focus has been on the workability of the fresh mortars as well as the pore structure of the carbonated plaster. The craftsmanship, meaning mixing and application of mortar and working the plaster surface, was studied in order to clarify its final pore structure. The pore structure in a material determines many of its technical properties, such as moisture transportation, compressive strength, permeability and frost resistance. All these properties are closely connected to the durability of the mortar and plaster. The permeability of the plaster has an impact also on the durability of the covered construction materials. Behind low-permeable plasters made with hydraulic binder, examples of extensive damages of rotten wood and leached lime have been shown. The investigations have shown the importance of choosing a mortar adjusted to the building construction. They also showed the importance of choosing a blending ratio adjusted to the specific binder and sand used in order to get a mortar with a suitable pore structure and good durability. It has also shown the importance of knowing when and how to work on the plaster surface in order to obtain a homogenous material that is well receptive for lime wash and has a good frost resistance. The combination of all the investigations has led to a method for reconstructing historic mortar and plaster with good durability.

Place, publisher, year, edition, pages
Göteborg: Chalmers Tekniska Högskola, 2007. 94 p.
Keyword
lime plaster, lime mortar, masonry, craftsmanship, pore structure, frost resistance, historic mortar
National Category
Natural Sciences
Research subject
Conservation (HGO)
Identifiers
urn:nbn:se:uu:diva-220119 (URN)9789172919907 (ISBN)
Public defence
2007-09-27, Wisby Strand, Visby, 09:00 (Swedish)
Opponent
Supervisors
Funder
Knowledge Foundation
Available from: 2014-04-16 Created: 2014-03-11 Last updated: 2014-04-16Bibliographically approved

Open Access in DiVA

fulltext(2844 kB)336 downloads
File information
File name FULLTEXT01.pdfFile size 2844 kBChecksum SHA-512
91e2d833843d306508ddebdfe964f7a21a553a5d9fe85a4db652a4031d31704cf7962c492004bad9049cbb3771b3f6b5db2deb125d943adc7865f7d43f4dddd3
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Balksten, Kristin
Other Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 336 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 471 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf