Component One: Nanostructure and Irreversible Colloid Behavior of Lime (Calcium Hydroxide) as Observed in Slaked Lime and Hydrated Lime
This study demonstrated that hydrated lime could be one of the first nanomaterials used by humans. The nano-particles impart a colloidal nature to the lime putty that is irreversible. The observed irreversible colloid behavior associated with drying of Ca(OH)₂ dispersions has important implications in heritage conservation, particularly considering that currently hydrated lime is often the preferred alternative to Portland cement in architectural conservation.

Component Two: Comparison of Slaked Lime Putties and Commercial Dry Hydrated Lime
Many architects and architectural conservators specify the use of lime putties slaked directly from calcium oxide as opposed to commercially available dry hydrated lime. The results of standard tests applied to putties and mortars made with slaked lime and dry hydrated lime add to the general technical knowledge on which to base decisions for their appropriate use.

Component Three: Aging of Lime Putty
Aging of lime putty, by storing slaked lime under excess water for extended periods of time, has been recognized for centuries as a means to improve the quality of lime as a binder in lime-based mortar and plasters. A model for portlandite crystal evolution during storage was developed that explains the working properties of the putty, carbonation rates of the binder, and physical properties of mortars.

Component Four: Carbonation of Lime
The hardening of lime due to carbonation is responsible for the increase of strength and the development of the pore system. The carbon dioxide concentration (uptake) was measured to identify the kinetics of the reaction and to model the carbonation process in general. The carbonation process also has an effect on the hardening of calcium silicate binders, where changes of mineral phases and microstructures of hydraulic binders with time have an influence on the strength development and durability of mortars.

Component Five: Effects of Organic Additives
The need for compatible materials for historic building conservation led to the revival of traditional techniques of preparing lime mortars, including the addition of organic additives. A number of natural and artificial additives will be studied for their effect on workability and mortar durability, with the ultimate aim of designing new conservation lime mortars with superior physical-mechanical properties.

Component Six: Weak Lime Mortars Add to Sustainable Masonry Construction
The objective of this study was to clarify the tri-axial behavior of mortar in masonry structures in order to elucidate that which previous masonry models had been unable to explain with uni-axial compression testing. Lime mortars are better able to adapt to differential settlements, and this is the result of their deformability and weakness (ability to be compressed that results in more energy absorption).

Last updated: October 2007