Effect of application of lime plasters to salt-laden bricks

0462129 - ÚTAM 2017 RIV FR eng C - Konferenční příspěvek (zahraniční konf.)
Nunes, Cristiana Lara - Slížková, Zuzana
Effect of application of lime plasters to salt-laden bricks.
International RILEM Conference on Materials, Systems and Structures in Civil Engineering. Segment on Historical Masonry. Paris: RILEM Publications, 2016 - (Rörig-Dalgaard, I.; Ioannou, I.), s. 117-126. RILEM Proceedings PRO, 110. ISBN 978-2-35158-174-2.
[International RILEM Conference on Materials, Systems and Structures in Civil Engineering. Conference segment on Historical Masonry. Lyngby (DK), 22.08.2016-24.08.2016]
Grant CEP: GA MŠMT(CZ) LO1219
Klíčová slova: lime plaster * salt-laden bricks * historic mortars
Kód oboru RIV: AL - Umění, architektura, kulturní dědictví

Historic masonry is usually contaminated with soluble salts that change the properties of the original materials. The design of mortars for historical repairs should, therefore, take this condition into account. The aim of this study is to investigate the performance of lime plasters cured on a salt laden substrate. A lime mortar (L) and a lime mortar with a traditional hydrophobic admixture (LO) were applied to sodium sulphate laden bricks, and the properties of the plaster/brick systems were examined after curing. The results indicated that L mortar works as a salt-transporting plaster, whereas LO functions as a salt-blocking plaster and the salt accumulates preferentially at the interface between the plaster and the brick. The capillarity curves showed that the hydrophobic effect of LO plaster was significantly affected despite the small amount of salt that migrated from the brick to the plaster during curing. No change in the water absorption kinetics was observed for L plaster cured on a salt-laden brick and the drying process was only slightly altered while it extracted more than 50 wt.% of the salt initially present in the brick. In contrast, the hydrophobic plaster significantly reduced the drying rate in both salt-free and salt-contaminated bricks.
Trvalý link: http://hdl.handle.net/11104/0261642