In recent years several types of restoration plasters, especially developed for salt loaded substrates, have been introduced on the market. The behaviour of these plasters in the field is, however, ...not always satisfactory. The reasons for failures may be found both in the moisture and salt transport behaviour of the substrate/plaster combination and in the severity of the situation (salt load, moisture supply and environmental conditions).
In the present paper a restoration plaster for salt loaded substrates is examined. Its properties and composition are investigated in laboratory by means of multiple techniques (MIP, PFM, ESEM, XRD and FTIR). Particular attention is given to the study of the salt (NaCl) crystallization in the plaster. Field situations are considered in which this plaster shows damage after a few years from its application. The knowledge of the specific situation, together with the information gained in the laboratory research on the plaster, explains the fast development of the decay.
The present paper reports the results of a series of investigations and monitoring performed, during a period of more than three years, on an ancient church flooded by the sea 50 years ago. This ...building can be considered representative for many other brick-masonry monuments in the flooded areas in the Netherlands. The church, restored several times in the past 50 years, shows a serious decay mainly affecting the restoration plaster applied in the interior; the damage appeared few years after the application of the plaster and has considerably increased in time.
The research described in the present paper aims to reach better understanding of the mechanisms through which damage occurs in order to find out the reasons of the unsuccessful repairs performed in the past and to propose possible solutions to stop or slow down the decay process.
Plasters and renders for salt laden substrates van Hees, Rob P.J.; Naldini, Silvia; Rodrigues, Jose Delgado
Construction & building materials,
05/2009, Letnik:
23, Številka:
5
Journal Article
Recenzirano
The EU project COMPASS, Compatibility of Plasters and renders with Salt loaded Substrates in historic buildings, aimed at improving the maintenance of monuments by means of a better understanding of ...the working principles of the plasters and the damage mechanisms induced by salt crystallisation. Salt damage was effectively studied modelling the moisture and salt transport and degradation (irreversible dilation) and a fast and efficacious salt crystallisation test developed. Practical results were the assessment of the requirements for plasters to be used on salt loaded substrates and guidelines for selecting plasters suitable for different situations. The dissemination of the results was also entrusted to the expert system MDDS.
