Lime-based mortars with a traditional water-repellent admixture: a study on degradation phenomena

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F15%3A00240802" target="_blank" >RIV/68407700:21110/15:00240802 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Lime-based mortars with a traditional water-repellent admixture: a study on degradation phenomena

Popis výsledku v původním jazyce

This thesis investigates the performance of lime-based mortars with the addition of linseed oil as a water-repellent admixture. The literature review revealed that all the ancient documents mentioning the use of hydrophobic admixtures for mortars report or recommend its application in severe weathering conditions involving water transport. It was also clear that there is a lack of scientific literature on the use of vegetable oils as admixtures for lime-based mortars to use in the repair of architectural heritage. In this study, linseed oil was selected owing to its common use throughout the history, to its worldwide availability and environmentally-friendly nature, and to the compelling results obtained in previous research. Linseed oil was added to two mortar mixtures: air lime and air lime with metakaolin. First, the properties and durability assessed by salt crystallisation and freeze/thaw cycles were studied in standard mould mortar specimens. Second, the mortars were applied as plasters on a fired-clay brick. The addition of oil to the mortars neither significantly changed the porosity, mechanical strength nor the drying kinetics, while significantly decreased the water absorption by capillarity, thus improving the resistance to salt crystallisation and freeze/thaw cycles. The lime mortars showed higher resistance to salt degradation, whereas the lime-metakaolin mortars revealed higher resistance to frost damage. Therefore, the lime mortars applied as plasters on brick were selected to expose to salt crystallisation cycles, and the lime-metakaolin plaster/brick systems were chosen to expose to freeze/thaw cycles. The mortars formulated were applied as plasters/renders in three case studies which provided insight into practice-related degradation problems. The effect of the application of the lime plasters on a salt-laden brick was also studied. The results obtained showed that the lime plaster favours the salt transport towards the surface where it crystallis

Název v anglickém jazyce

Lime-based mortars with a traditional water-repellent admixture: a study on degradation phenomena

Popis výsledku anglicky

This thesis investigates the performance of lime-based mortars with the addition of linseed oil as a water-repellent admixture. The literature review revealed that all the ancient documents mentioning the use of hydrophobic admixtures for mortars report or recommend its application in severe weathering conditions involving water transport. It was also clear that there is a lack of scientific literature on the use of vegetable oils as admixtures for lime-based mortars to use in the repair of architectural heritage. In this study, linseed oil was selected owing to its common use throughout the history, to its worldwide availability and environmentally-friendly nature, and to the compelling results obtained in previous research. Linseed oil was added to two mortar mixtures: air lime and air lime with metakaolin. First, the properties and durability assessed by salt crystallisation and freeze/thaw cycles were studied in standard mould mortar specimens. Second, the mortars were applied as plasters on a fired-clay brick. The addition of oil to the mortars neither significantly changed the porosity, mechanical strength nor the drying kinetics, while significantly decreased the water absorption by capillarity, thus improving the resistance to salt crystallisation and freeze/thaw cycles. The lime mortars showed higher resistance to salt degradation, whereas the lime-metakaolin mortars revealed higher resistance to frost damage. Therefore, the lime mortars applied as plasters on brick were selected to expose to salt crystallisation cycles, and the lime-metakaolin plaster/brick systems were chosen to expose to freeze/thaw cycles. The mortars formulated were applied as plasters/renders in three case studies which provided insight into practice-related degradation problems. The effect of the application of the lime plasters on a salt-laden brick was also studied. The results obtained showed that the lime plaster favours the salt transport towards the surface where it crystallis

Druh

O - Ostatní výsledky

CEP obor

JN - Stavebnictví

OECD FORD obor

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Projekt

<a href="/cs/project/DF11P01OVV008" target="_blank" >DF11P01OVV008: Vysokohodnotné a kompatibilní vápenné malty pro extrémní aplikaci při restaurování, opravách a preventivní údržbě architektonického dědictví</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů