Effect of application of lime plasters to salt-laden bricks

Author(s): Cristiana Nunes and Zuzana slizkova
Paper category: Proceedings
Book title: Proceedings of the International RILEM Conference
Materials, Systems and Structures in Civil Engineering 2016 segment on
Historical Masonry
Editor(s): Inge Rörig-Dalgaard and Ioannis Ioannou
ISBN: 978-2-35158-178-0
e-ISBN: 978-2-35158-179-7
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 130-139
Total Pages: 10
Language : English

Abstract: 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.

Online publication : 2016
Publication type : full_text
Public price (Euros) : 0.00