Adhesion and rheology of fresh mortar joints: effects of organic additions
An adhesive mortar in fresh state is considered as a granular suspension in a complex fluid. The study of the rheological behavior of such materials involves the rheology of complex fluids, including granular suspensions, colloidal dispersions, etc... To characterize the rheological behavior of an adhesive mortar, in quasi-static regime, we use a three-parameter behavior law that includes a yield stress, a viscosity coefficient and a fluidity index. The adhesiveness of the mortar can be characterized by identifying the evolution of the adhesive force, the cohesive force and the adherence force. The mortar characteristics are measured by a commercial rheometer from Texas Instruments (TA). In this study, we use a plane-plane geometry for the Probe Tack Test to determine the adhesiveness of the materials. The rheological property of the mortar is investigated using the Vane-Cylinder geometry. The mechanisms of separation and rupture in a tensile material confined between two parallel plates are studied theoretically and experimentally. This study is conducted for a materials selected for his rheological behavior (Herschel Buckley). We studied the rheological behavior and the influence of additions of organic additives on the rheological parameters intrinsic to the material, and the failure mechanisms. This study has allowed us to observe the different types of rupture.