Rheological behavior analysis of rendering mortars using the squeeze-flow method on various substrates

Abstract

The research aimed to evaluate the rheological behavior of mixed rendering mortars (mix ratio 1:1:6, cement:lime, by volume), industrialized, and stabilized mortars when applied to different substrates. The mortars were characterized in their fresh state, and their rheological behavior was assessed using the squeeze-flow method, employing a metal base, a ceramic block, and plaster applied over the ceramic block, at speeds of 0.1, 1, and 3 mm/s. Force-displacement curves were plotted, and from these, analyses of the transitions between the elastic, plastic, and yield stages of the mortars were conducted. The results indicated that the stabilized mortars exhibited more extensive plastic phases compared to the others across all types of substrates. All analyzed mortars demonstrated a reduced spreading capacity with increased initial water absorption and roughness of the substrates. Although there are normative limitations, the rheological behavior of the mortars was influenced by both their characteristics and the substrates. The squeeze-flow test on the ceramic block and plaster highlights the need to consider the diversity of substrates for analyzing the behavior of rendering mortars and to provide improved construction practices.

Keywords
Rheology; Rheological Behavior; Coating mortars; Rendering mortars; Squeeze-flow; Roughness