Mineralogical and geochemical studies of secondary mineral assemblages related to deterioration of building materials

Abstract

and Tech nol ogy, Fac ulty of Ge ol ogy, Geo phys ics and En vi ron men tal Pro tec tion, al. A. Mickiewicza 30, 30-059 Kraków, Po landMarsza³ek, M., Dudek, K., Gawe³, A., Czerny, J., 2019. Min er al og i cal and geo chem i cal stud ies of sec ond ary min eral as semblages re lated to de te ri o ra tion of build ing ma te ri als. Geo log i cal Quar terly, 63 (4): 683-698, doi: 10.7306/gq.1494The study was aimed at min er al og i cal and geo chem i cal char ac ter is tics of sec ond ary phases re lated to de te ri o ra tion of historic build ing ma te ri als. The in ves ti ga tions, car ried out in the Holy Trin ity Ba sil ica in Kraków, Po land, fo cused on the south ern facade of the 17th-cen tury Myszkowskis Cha pel, built of the Mio cene Piñczów lime stone. Lower part of the facade is cov ered with a ce ment ren der, and the ex posed foun da tions are made of Ju ras sic lime stone and Cre ta ceous sand stone, both of lo cal or i gin from the Kraków re gion and neigh bour ing Carpathians, in the form of ir reg u lar blocks bound with a ce ment mor tar. The wall sur face ex hib its clear signs of dam age; from dark grey soil ing and scal ing to efflorescences. Sam pled ma te ri als, de te ri orated, al tered crusts and efflorescences were an a lysed with op ti cal and scan ning elec tron mi cros copy, X-ray dif frac tion, and Raman microspectroscopy meth ods. The sec ond ary min er als dis tin guished in clude abun dant gyp sum CaSO 4 ·2H 2 O, less com mon thenardite Na 2 SO 4 (and/or mirabilite Na 2 SO 4ÿ 10H 2 O), aphthitalite (K, Na) 3 Na(SO 4 ) 2 , darapskite Na 3 (SO 4 )(NO 3 )·H 2 O, ettringite Ca 6 Al 2 (SO 4 ) 3 (OH) 12 ·26H 2 O, monosulphite Ca 4 Al 2 O 6 SO 3 ·11H 2 O, as well as scarce ni tre KNO 3 , nitratine NaNO 3 and ha lite NaCl. Gyp sum usu ally forms sur face crusts and fills the pores in side some ma te ri als. The efflorescences, sam pled from the ex posed foun da tions, con sisted of thenardite and/or mirabilite, aphthitalite and darapskite, whereas ettringite and monosulphite were con nected with ce ment ren ders. Traces of ni tre, nitratine and ha lite were de tected at var i ous el e ments of the cha pel facade and foun da tions. The or i gin of the salts is re lated to com po si tion and physicochemical prop er ties of the build ing ma te ri als, as well as to anthropogenic fac tors.

Cement Render and Mortar and Their Damages Due to Salt Crystallization in the Holy Trinity Church, Dominicans Monastery in Cracow, Poland

“…Minerals 2020, 10, x FOR PEER REVIEW 3 of 19 rusticated Pińczów limestone, but any detailed information about the other elevation materials was not encountered. In the course of our previous research [20], we observed that the stony elements below the rusticated blocks of the Pińczów limestone were also covered with a thin layer of a beige-brown, highly exfoliated cement render. However, some of the limestone blocks in the row of the façade below the small shaft contained replacements and thick, bright render of a different nature than the previous.…”

“…The latter will then first precipitate darapskite and, in the end, nitratine. Nitrate salts-nitratine NaNO 3 and nitre KNO 3 -have been detected on the surface of the Jurassic limestone in the vicinity of the efflorescence [20]. Aphthitalite (K,Na)3Na(SO4)2, in EDS analyses revealing the presence of Na, K, S and O, occurs in the form of anhedral, often isometric crystals and irregular aggregates, as shown in Figure 11c.…”

“…The latter will then first precipitate darapskite and, in the end, nitratine. Nitrate salts-nitratine NaNO3 and nitre KNO3-have been detected on the surface of the Jurassic limestone in the vicinity of the efflorescence [20]. The ions of crystallized sodium, potassium, calcium sulphate, and sulphate-nitrate salts may come from both internal and external sources-natural and anthropogenic ones.…”

“…The presented study began during conservatory works in 2017, thanks to the courtesy of the Monastery authorities and Mr Bartłomiej Polczyński. Some of the results were published in 2019 [20]. Current research was focused on a bright render, in places covering the limestone blocks and filling the material losses (lower part of the façade wall, just above the bright blocks, close to the pavement level) and mortar that bound and partly replaced the stones in the chapel subwall, below the pavement line.…”

Rare Occurrence of Mirabilite in the Thirteenth-Century Historic Salt Mine in Bochnia (Poland): Characterisation, Preservation, and Geotourism

“…It is found in the sodium sulphate deposits in the Northern Great Plains of Canada, on the surface of playa lakes in Central and Northeast Spain and on the dry shores of the Aral Sea (Valero-Garcés et al 2000;Kelley and Holmden 2001;Crétaux et al 2009;Cabestrero et al 2018). However, the crystallisation of mirabilite due to the moisture present in the pores in masonry is regarded as a harmful process resulting from salt precipitation on building materials (Ruiz-Agudo et al 2007;Marszałek et al 2019). It has been identified that the precipitation of mirabilite and other similar salts is provoked by the freezing processes that occur in the glacial or subglacial bodies of water in Antarctica (Liu et al 2015).…”