Influence of Water Content and Mixing Conditions on the Properties of Lime-Based Materials

This paper evaluates the influence of water content and mixing conditions (mixing time and sequence of addition of the constituents) on the fresh state properties of lime-based materials and their impact on the hardened state properties. Higher water contents allowed an increased fluidity and lower torque, yield stress and plastic viscosity values. In turn, a longer mixing time with the aggregate caused a progressively stiffer mortar and a substantial increase in the torque, yield stress and plastic viscosity values due to the breakdown of lime agglomerates that consume part of the free water available to lubricate the mix. A longer mixing time without the aggregate caused similar trends, albeit to a much lesser extent. The water content and mixing conditions also had a major impact on the resulting porous structure of lime mortars and, thus, on their mechanical strength.