60 Works

Salt crystallization resistance of nano-modified repair lime mortars

M. Theodoridou, L. Kyriakou & I. Ioannou
This paper describes the results of the application of nano-binders (SiO2 and TiO2) in repair lime mortars, focusing on the durability of the composites against salt crystallization. A total of 12 new mixtures have been designed, produced and investigated in the laboratory, in an effort to produce durable, environmentally friendly, energy-efficient, sustainable composites, primarily for conservation purposes but also for contemporary applications. The effect of different aggregates and binders on the end-product was also investigated...

Common salt mixtures database: a tool to identify research needs

S. Godts, R. Hayen & H. De Clercq
Salt mixtures found in building materials and stone sculptures have been analyzed in the Monuments Laboratory at KIK-IRPA since the early 1960’s. The common salt mixtures database is a spreadsheet based on the results of quantitative ion analyses carried out with Ion Chromatography at KIK-IRPA since 2004, currently counting almost 6000 records of samples from Belgian monuments and sculptures, e.g., about 1600 brick and mortar samples, 300 wall plaster and 581 natural stone samples. Today,...

Drying of porous building materials possibly contaminated with soluble salts: summary and findings of the DRYMASS research project

T. Diaz Gonçalves, V. Brito, J. Musacchi, L. Pel, T. Saidov, J. Delgado Rodrigues & J.M. Mimoso
Moisture causes severe and recurring anomalies in the built heritage, but removing it from the solid and thick masonry walls of old constructions is not easy, especially when soluble salts are present. These salts crystallize during drying, may harm the materials and their aesthetics. Moreover, the salts themselves and the alterations they cause affect the underlying drying process through mechanisms that require clarification. The DRYMASS project aimed at improving the current understanding of drying and...

Modellhafte Präventive Konservierung von umweltgeschädigten Sandsteinsäulen und -kapitellen aus der Frührenaissance in der St. Annenkirche in Ruppertsgrün

Thomas Löther & Matthias Zötzl
Zur hochrangigen Innenausstattung der St. Annenkirche in Ruppertsgrün gehören acht originale Sand-steinsäulen aus Zwickauer Kohlesandstein. Diese Natursteinarbeiten stehen einerseits für eine erste Verwendung von Renaissance-Elementen im Bereich der ländlichen Architektur in Sachsen, andererseits zeigen sie gravierende Schäden und einen rasanten Schadensfortschritt aufgrund einer anthropogenen Schadbelastung und problematischen raumklimatischen Umweltbedingungen. Durch erste Vorun-tersuchungen konnte belegt werden, dass die zu DDR-Zeiten installierten Außenwandgasheizkörper stark negative Auswirkungen auf die mittlerweile durch die Verbrennungsrückstände schadsalzbelasteten und empfindlichen Natursteinoberflächen der...

Konservierung-Restaurierung des mehrfach überarbeiteten Gemäldes „Musizierende Nymphen und Putti“ von Giulio Carpioni, Öl/Lwd., 98,5 x 118,4 cm (KHM Wien)

Katharina Hatzl
Die Arbeit beschäftigt sich mit der Konservierung und Restaurierung eines vorwiegend durch frühere restauratorische und konservatorische Maßnahmen beeinträchtigten Gemäldes. Die Veränderungen und Eingriffe am Gemälde wurden untersucht und mit der Restaurierungs- und Ausstellungsgeschichte der Gemäldegalerie des Kunsthistorischen Museums Wien in Verbindung gebracht. Im Zuge einer umfangreichen Testreihe wurde ein Lösungsmittelsystem für die Abnahme der Übermalungen entwickelt. Ein weiterer Teil der Arbeit umfasst die Untersuchung farblich veränderter Bildpartien. Anhand materialanalytischer Untersuchungen konnte eine Bleiweißverseifung festgestellt werden.

Porosity changes after different temperature regimes for a salt weathering simulation test on Mokkattam limestone (Egypt)

N. Aly, M. Gomez-Heras, A. Hamed, M. Alvarez De Buergo & F. Soliman
This study deals with the characterization of the pore structure of fresh quarry limestone samples belonging to the Mid-Eocene Mokattam Group, and porosity changes in samples subjected to salt crystallization tests at different temperatures (20, 30 and 40 °C) in a purpose-made simulation chamber based on feeding samples by capillary imbibitions. NaCl with fixed concentration (10%) was used in the different experimental tests. One more experiment was performed using only distilled water to discriminate changes...

Measurement of sorption isotherm of porous materials influenced by salt

M. Abukuas, O. Ogura, S. Hokoi, C. Iba, S. Wakiya & T. Uno
This paper compiles the past data of the sorption isotherm of Autoclaved Aerated Concrete (AAC) laden with salts (MgCl2 and NaCl) and some new experimental data for AAC that contains Na2SO4. The results are related to the type of salt, the salt concentration and the mass of salt that is considered to be crystallised. Finally the existing mathematical model that uses the sorption isotherm for pure water and the salt content in the material is...

Study of NaCl crystallization using Infrared Thermography

P. Vázquez, C. Thomachot-Schneider, K. Mouhoubi, M. Gommeaux, G. Fronteau & V. Barbin
The Infrared Thermography (IRT) technique has been widely developed during the last years. IRT is useful to observe changes in the fields of physics and chemistry, and has turned out to be an important and indispensable non-destructive technique used for investigation of civil engineering works, with special attention to cultural heritage. In this research IRT has been used to study the crystallization of NaCl solution droplets with different initial concentrations (3.5, 14 and 26% weight)....

Numerical simulation of gypsum transport and crystallization

J. Todorović & H. Janssen
Over the last few decades, brick masonry buildings in the UK, The Netherlands and Belgium have started suffering from a new type of salt efflorescence. This new efflorescence consists of sparingly soluble gypsum, and is therefore strongly persistent. Although gypsum efflorescence has already been known for several decades, there are still many open questions regarding the mechanisms behind this phenomenon. Numerical simulation of the transport and crystallization of gypsum in porous materials can contribute to...

Gypsum efflorescence under laboratory conditions: preliminary studyH

J. Chwasts, H. Janssen & J. Elsenas
Gypsum efflorescence (GE) is a recent problem affecting modern clay brick masonry and permanently alters an aesthetic aspect of a building. This type of efflorescence affects exclusively masonry built in the last 30 years and usually appears a couple of years after construction. The GE characteristics indicate that the components are derived from the masonry itself and not from the atmosphere. The GE genesis and mechanism, and specifically the gypsum crystallisation behaviour in porous materials,...

Influence of the salt concentration on the damage potential of mirabilite and thenardite

A. Stahlbuhk, J. Nissen, K. Linnow & M. Steiger
The present study reports on the damage potential of the crystallization of either thenardite or mirabilite in porous sandstone. Specimens of Sand sandstone with different loads of sodium sulfate were exposed to wetting-drying cycles at different conditions to rank the damage potential of different crystallization pathways and to investigate the influence of the salt concentration on the damage process. The damage intensity was assessed by visual inspection and mass loss curves. In general, the well-known...

Das UNESCO-Welterbe und die Rolle der Zivilgesellschaft.

Dömpke, Stephan (Hg.)
Am 25./26. Juni 2015 organisierte World Heritage Watch in Bonn die internationale NGO-Konferenz "Das UNESCO-Welterbe und die Rolle der Zivilgesellschaft". Sie folgte dem ersten NGO-Forum zum Welterbe, das 2012 in St.Petersburg stattgefunden hatte. Ziele der Konferenz waren: 1. Bewertung der Situation ausgewählter Welterbestätten aus der Sicht der Zivilgesellschaft, insbesondere im Hinblick auf negative anthropogene Umwelteinflüsse. 2. Information der deutschen und internationalen Öffentlichkeit über Fortschritte und Herausforderungen bei der Umsetzung der UNESCO-Welterbekonvention aus Sicht der Zivilgesellschaft....

Long-term Monitoring of Salt Movement in Masonry Materials

Jürgen Frick, Camilla Colla, Elena Gabrielli & Friedrich Grüner
Presentation of SiK-Conference Aktuelles aus Forschung und Praxis zum Thema Salz, 31.03-02.04.2016, HfBK Dresden

Determination of the deliquescence point in salt mixtures and in in-situ multicomponent salts with DVS equipment

I. Rörig-Dalgaard
Accelerated salt induced deterioration occurs by frequently changes across the deliquescence point. Therefore does the actual deliquescence point of the present salts have a major impact on preventive conservation being able to ensure a relative humidity not causing salt phase transition and to in-situ desalination as dissolution of the salts is the essential criterion to enable transport of salt (ions) in the construction. In the present work deliquescence points were measured with dynamic vapor sorption...

The UNESCO World Heritage and the Role of Civil Society.

Doempke, Stephan (Ed.)
On 25-26. June 2015 World Heritage Watch organized the International NGO Conference "The World Heritage and the Role of Civil Society" in Bonn, Germany. It followed the first NGO Forum on World Heritage 2012 in St.Petersburg. The objectives of the conference were: 1. To review the situation of selected World Heritage sites from the perspective of civil society, particularly with regard to negative anthropogenic environmental influences. 2. To inform the German and international public of...

Effect of ethyl silicate on salt crystallization resistance of Maastricht limestone

B. Lubelli, R. P. J. Van Hees, T. G. Nijland & J. Bolhuis
Consolidant treatments aim to re-establish the cohesion in decayed materials showing decay patterns as sanding or powdering. Ethyl silicate (TEOS) is the most used type of consolidant for inorganic porous materials in the last 30 years. This product, which works through precipitation of silica gel in the pores of the material, is known to have a good chemical compatibility with siliceous substrates (sandstone and brick), but much less with lime based materials as limestone and...

Long-term Monitoring of Salt Movement in Masonry Materials

Jürgen Frick, Elena Gabrielli, Camilla Colla & Friedrich Grüner
The recrystallization of salts due to changes in moisture content is one of the major damage functions in historic materials like natural stones, tiles, plasters, and mortars. This paper presents results of a long-term wireless monitoring of salt and moisture movement at a test wall. Within the EU-project “Smart monitoring of Historic Structures – SMooHS (www.smoohs.eu), a potential difference measurement node was developed in combination with ion-selective electrodes based on silver/silver-chloride for the detection of...

Jahresbericht 2015

Angela Weyer
Jahresbericht des Hornemann-Instituts als wissenschaftliche Service-Einrichtung im Bereich Erhaltung von Kulturgut / Annual report of the Hornemann Institute, a scientific service center in the field of conservation and restoration

Salzminderung an Cottaer Sandstein mit angepassten Kompressen

Julia Maitschke
Präsentation der SiK Tagung Aktuelles aus Forschung und Praxis zum Thema Salz, 31.03-02.04.2016, HfBK Dresden

Die neuen Förderleitlinien der Deutschen Bundesstiftung Umwelt

Paul Bellendorf
Präsentation der SiK Tagung Aktuelles aus Forschung und Praxis zum Thema Salz, 31.03-02.04.2016, HfBK Dresden

Investigating a method to limit damage in Globigerina Limestone, a soft porous stone widely used in historic buildings

S. Sammuts, J. Cassar, A. Marrocchi, C. Russo, L. Sommei & M. L. Santarelli
A programme of studies is ongoing to investigate the action of environmentally-friendly functionalized polycarboxylates as organic crystallization modifiers on salts on two types of Globigerina Limestone of Malta, to compare their action and behaviour. This was mainly done to verify the potential of such compounds to control, and therefore, limit damage on this locally unexplored territory. The main thrust of the research, at this stage, was to observe modifications to solution transport and salt crystal...

Salt conversion, backfilling, and back anchoring: the securing of the painted ceiling of the Red Hall in the Neues Museum, Berlin

W. Wedekind & J. Rüdrich
In connection with the restoration of the Red Hall in the Neues Museum, located on the museums-island in Berlin (2006-2008), a procedure for salt conversion and backfilling of hollow painted plaster areas with the help of low-pressure injection technology was developed and successfully implemented. The precipitation reaction resulting from the salt conversion was assessed using electrical conductivity measurements and identification of the precipitate by x-ray diffractometric analyses (XRD). For an additional securing of the plaster...

In-situ "vacuum" desalination - case study of a baroque tombstone

H. Siedel, C. Franzen & E. Pummer
A combined "vacuum" and poultice desalination procedure was applied to a tombstone made of Cotta sandstone. The desalination steps were controlled analytically by salt profiles in the stone, as well as by analyses of waste water and poultice material. A remarkable reduction of high total salt contents to a depth of 1-2 cm could be achieved, with the best effects in the lower part of the monument (at 50 cm height). In particular, high gypsum...

Further steps towards the solution of Correns’ dilemma

F. Caruso & R. J. Flatt
Correns’ and Steinborn’s pioneering experiment is probably the most intriguing one in the field of salt crystallization. It consisted of the measurement of the force needed to prevent a monocrystal of potassium alum (potassium and aluminium sulfate dodecahydrate, KAl(SO4)2∙12 H2O) from growing in various supersaturated solutions. What is puzzling is that they obtained very good agreement between their experimental data and an ideal equation of crystallization pressure. We report here the experimental advances in our...

Testing the durability of hemp-based mortars under Mediterranean climatic conditions in coastal and inland areas: does the presence of salt alter hemp bio receptivity?

A. Arizzi, H. Viles, I. Martin-Sanchez & G. Cultrone
In this study, we assessed the durability of hemp-based mortars by means of accelerated weathering tests, simulating coastal and inland areas with a Mediterranean climate. Mortars were produced with dry hemp hurds (i.e. inner part of the stem) and three binders: dry hydrated lime, lime putty and natural hydraulic lime. Simulation of temperature and relative humidity variations, rainfall and salt attack were carried out in an environmental cabinet and programmed according to the Mediterranean climatic...

Registration Year

  • 2016
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  • Text
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