The Influence of Water Content on the Fresh and Hardened State Properties of Lime-Pozzolan Grouts

Lime-pozzolan grouts concern a specific type often applied in the restoration of historic structures. Their water content, a crucial factor of their applicability, has a significant impact on their fresh and hardened state properties. In this study, four grout compositions were manufactured and tested, consisting of hydrated lime and natural pozzolan in a mass proportion 1:1. Their fresh properties were recorded, including fluidity, penetrability, volume stability, viscosity and shear stress, as well as the hardened ones (shrinkage deformations, physical and mechanical characteristics). Results show that water content reduction led to an increase in flow and penetration time, as well as a significant decrease of volume changes. Mechanical properties were significantly enhanced. Generally, the water content played a fundamental role in the behavior of the mixtures, also defining the type and range of their application.