Comparison of hardening kinetics by small amplitude oscillatory rheometry in the case of alkali activated kaolinitic clays

In this study, the rheological behaviour of geopolymeric inorganic binders were determined. These binders were synthesized by alkaline activation of aluminosilicate material. Five kaolinite clays were chosen for investigation and as an alkaline activator of hardening process, the potassium silicate solution with silicate module of 1.61 was used. For increase of reactivity, the kaolinite clays were calcined by heat treatment at 600 degrees C for 4 hours and converted to metakaolin state. The particle size of individual materials was determined by measurement of laser light scattering. The rheological properties were determined in accordance to flow properties by measurements on Ford viscosity cup and by strain controlled small amplitude oscillatory rheometry measurements at 30 degrees C isotherm and the hardening process evolution was documented by measurement of complex viscosity. The effects of granularity and accessory minerals on flow and hardening properties are discussed.