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

Mariola MARSZAŁEK, Krzysztof DUDEK, Adam GAWEŁ, Jerzy CZERNY
2019 Geological Quarterly  
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 land Marsza³ek, 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.1494 The 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
more » ... 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.
doi:10.7306/gq.1494 fatcat:s3ubtmnv5zdmppxhn77444nfwy