Throughout the lifetime of historic buildings the masonry will often undergo at least one conservation intervention. The need for conservation arises from the different elements of the building and to this end mortars have a very important role to play. Historic lime mortars and the various components from which they are made including the type of lime, pozzolan and aggregates have been extensively studied. They have received attention concerning their degree of reactivity and how they interact with the masonry units which are commonly stone or brick. The pozzolan-lime reactions, and the hydration and carbonation processes are important factors that influence the final properties of any lime-pozzolan mortars. In this study lime-pozzolan paste combinations are defined as a combination of calcium lime (CL 90) with a pozzolanic additive. The pozzolanic materials; wood ash, brick dust and Argical M1000 have been investigated in this study. To understand the role of the different pozzolans on the initial hydration reactions of the lime in pozzolan-lime pastes, the rheology and hydration kinetics were evaluated using a TA Hybrid Rheometer DHR – 2 and a Calmetrix I-Cal 4000 calorimeter respectively. In terms of kinetics evolution, Argical M1000, a type of metakaolin exhibited greater pozzolanic activity than wood ash and brick dust. Calorimetry and rheology tests have shown corroborative results regarding the initial hydration reactions of the pozzolan-lime pastes, different effects were observed for each type of pozzolan.
|Title of host publication
|Proceedings of the 5th Historic Mortars Conference
|Subtitle of host publication
|Jose Ignacio Alvarez, Jose Maria Fernandez, Inigo Navarro, Adrian Duran, Rafael Sirera
|Number of pages
|Published - 19 Jun 2019