Effect of mixed vs single brine composition on salt weathering in porous carbonate building stones for different environmental conditions

0461598 - ÚTAM 2017 RIV NL eng J - Článek v odborném periodiku
Menéndez, B. - Petráňová, Veronika
Effect of mixed vs single brine composition on salt weathering in porous carbonate building stones for different environmental conditions.
Engineering Geology. Roč. 210, August (2016), s. 124-139. ISSN 0013-7952. E-ISSN 1872-6917
Grant CEP: GA MŠMT(CZ) LO1219
Klíčová slova: salt weathering * limestone * environmental conditions * sodium chloride * sodium sulphate * calcium sulphate * salt mixture
Kód oboru RIV: AL - Umění, architektura, kulturní dědictví
Impakt faktor: 2.569, rok: 2016
http://www.sciencedirect.com/science/article/pii/S0013795216301879

The influence of different factors, brine composition, environmental conditions and pore structure, on salt weathering of porous carbonate building stones is investigated. The main goal of this study is to highlight the differences in weathering between single salts and a mixture of different salts. Two kinds of weathering mechanism are studied, the crystallization pressure and the deliquescence/recrystallization process. To achieve this purpose wetting and drying cycles and cycles varying relative humidity on samples containing salts were performed. The effect of total salt content with different salts and mixtures is simulated by weathering tests with solution of different compositions (NaCl, 6% in weight, Na2SO4·10H2O, 6% in weight, CaSO4 at saturation, and a mixture of them at total concentration of 6.2%). Weathering tests were performed at room temperature and 50 °C and under low and high relative humidity. The results show that the final weathering depends on a complex combination of three parameters: (i) environmental conditions, (ii) salt composition and (iii) petrophysical properties of stones, and general conclusions on the impact of each parameter can be drawn. An important result is that salt mixtures have a lesser impact on weathering during crystallization cycles: single salt brines, especially sodiumsulphate, producemoreweathering than complex brine compositions duringwetting and drying cycles. Conversely during variations on RH, samples with salt mixtures suffer more damage than samples weathered with a brine of single salt composition.
Trvalý link: http://hdl.handle.net/11104/0261210