Abstract
To overcome the limitations of pure air lime mortars, various strategies have been used since ancient times,including the addition of hydraulic binders, pozzolanic materials, and additives. Despite extensive research,uncertainty remains regarding the most appropriate lime-based mortar for each conservation or restorationintervention. To address this, the study compares nine lime-based formulations: a pure air lime mortar (reference),two with natural pozzolan, three with superplasticizer, two blended air lime-hydraulic lime mortars, and apure natural hydraulic lime mortar. Results indicate that the natural pozzolan used was not beneficial for air limemortars due to its low reactivity. Conversely, air lime mortars with superplasticizer presented reduced porosityand water absorption, and increased strength (but also stiffness), particularly at higher dosages, showing potentialas alternatives to blended air lime-hydraulic lime mortars. The latter displayed the greatest colour differencescompared to the reference mortar but similar mechanical and physical properties, especially for 25 %hydraulic lime (HL 5). Finally, the pure natural hydraulic lime (NHL 3.5) mortar exhibited the highest strength atearly ages but presented a distinct unimodal pore structure.
NETL
NSTL
Elsevier