Marco Ludovico-Marques
in
Contribuição para o Conhecimento do Efeito de Cristalização de Sais na Alterabilidade de Arenitos. Aplicação ao Património Edificado de Atouguia da Baleia
This work intends to be the beginning of a process of study about the importance of sandstones in Portuguese cultural heritage.
The author refers to important monuments all over the world and in Portugal where sandstones are widely used. Atouguia da Baleia village is an example and it constitutes the case study of the present work.
Most of the research work carried out in this Portuguese village was about a national monument, St Leonardo Church, which is an excellent example of the importance of salt crystallization weathering effects in sandstones.
An experimental study was carried out in samples collected from historical buildings and samples of lithotypes with similar petrographic, physical and mechanical properties, collected nearby. This study was complemented with investigation works carried out in situ blocks of St. Leonardo Church masonry walls.
The assessment of salt crystallization artificial ageing was carried out in sandstone samples. The results of the experimental research on the treated samples are presented, as well as the assessment of a preliminary consolidating treatment effectiveness on the monument.
Several sandstone samples were treated with chemical consolidating products and their physical and mechanical properties were then assessed and compared to the non treated samples, as well as the effect of salt crystallization artificial ageing. The effects of cyclic loading were also studied in treated and non treated samples, before and after salt crystallization ageing tests.
A global model of mechanical and physical behaviour of sandstones was designed to describe their performance before and after salt crystallization ageing in treated and non treated sandstone samples.