A comparative study into the performance of hot mixed and lime putty mortars with additions of metakaolin and brick dust pozzolans

This paper explores the properties of mortars where the principle binder is calcium hydroxide. Two distinct forms of the binder were used: a ‘hot mix’ consisting of quicklime (calcium oxide), and a slaked and matured lime putty mortar. The modifications of properties exhibited by the two binders with and without the addition of pozzolans, brick dust and metakaolin were established. This study has relevance because of the lack of empirical data on the performance of modified mortars of these types. The experimental evaluation of properties including the mortar compressive and flexural strengths and the bond strengths obtained with brick demonstrated that although the hot mixed lime mortars expressed some advantages in terms of porosity over the putty-based counterparts, there is no significant difference in performance regardless of the pozzolan added.