Conservation and restoration of historic mortars and masonry structures

0584464 - ÚTAM 2024 RIV CH eng M - Část monografie knihy
Nunes, Cristiana Lara - Faria, P. - Garcia, N.
Limewashes with vegetable oils: water transport characterisation.
Conservation and restoration of historic mortars and masonry structures. Vol. 42. Cham: Springer, 2023, s. 150-161. RILEM Bookseries, 42. ISBN 978-3-031-31471-1
Grant CEP: GA MŠMT(CZ) EF18_053/0016918; GA ČR(CZ) GA18-28142S
Institucionální podpora: RVO:68378297
Klíčová slova: lime * water-repellent additives * hydrophobicity * damp * drying * porous materials
Obor OECD: Materials engineering
https://doi.org/10.1007/978-3-031-31472-8_12

Limewashes have been used as finishing coats for walls since ancient times. Its protective, aesthetic, antiseptic properties and cost-efficiency are the ground for its worldwide application. The main drawback of lime-based paints is their low durability towards the action of water, particularly wind-driven rain. Additives that grant water-repellent properties have been added to these paints to overcome this issue. Among these additives, vegetable oils have been reported worldwide in ancient documents. In this work, three vegetable oils have been selected based on their composition and promising results in previous studies, global availability, and cost-efficiency: rapeseed, sunflower, and sunflower oil with high oleic acid content. Additionally, a commercial water-repellent lime putty with the addition of olive oil was included to prepare a limewash and compare it with the lab-prepared paints. Two types of stone with very different porous structures were used as substrates to compare the effect of the paints on their water transport properties. The substrate with higher porosity and wider pores showed promising results in terms of water-repellence and drying. In contrast, the stone with lower porosity and fine pores did not show good results. Based on this study, suggestions for further research to improve the performance of the paints in substrates with low porosity and narrow pore size distribution are given.
Trvalý link: https://hdl.handle.net/11104/0352374