Comparison of Slaked Lime Putties and Commercial Dry Hydrated Lime

Work Completed

This work was carried out at the Getty Conservation Institute and published as "Variations in High-Calcium Lime Putty and Mortar Properties Resulting from the Use of Freshly-Slaked Quicklime and Commercial Dry Hydrated Lime," The Proceedings of the 2005 International Building Lime Symposium, Orlando Florida, National Lime Association, by E. F. Hansen, K. van Balen, and C. Rodriguez-Navarro.


"Many architects and architectural conservators specify the use of slaked lime putties, as opposed to commercial dry hydrates, with little technical knowledge of the differences in working properties of the putties or curing behavior and properties of the carbonated mortars. Mortars prepared from two lime types (both high-calcium) were characterized by 1) identifying differences in the textural quality of the particles and rheological behavior of the putties; and 2) testing the rate of carbonation and development of mortar strength over time. These test results are compared to previous work on aged lime putty in order to add to the general explanation for slaked lime behavior versus that of the hydrate. The lower plasticity, similar water retention and slower rate of carbonation of the commercial hydrate can be correlated with the particle size distribution, surface area, and mass of lime present in the mortars (respectively). As slaked lime putty ages, the mass of lime per unit area in the putty increases along with changes in crystal form (from prisms towards plates) and size (particle size deceases), affecting the work properties and development of physical properties."

Page updated: October 2007