ROLE OF BINDER IN THE PROCESS OF GEOPOLYMERISATION OF RED MUD-BASED PRODUCTS

Process of geopolymerisation is based on the heterogeneous low-temperature chemical reaction (up to 100 degrees C) between the solid raw, silicate-rich materials and alkali solution in the presence of binder. The results of the reaction are compact high-strength products with the 3D polymer like structure. Geopolymerisation is the process that enables the valorisation of silicate materials (wastes dominantly) in the eco-friendly product that fits the construction purposes. The mechanism of geopolymerisation depends on several parameters such as: thermal regime, raw mixture content, Al/Si ratio in raw mixture, binder type and binder content. This paper presents the comparison of the mechanical characteristics of geopolymers produced by using of different types of binder in raw mixture with the aim to obtain satisfactory mechanical characteristics of the final product. Portland cement or metakaolin were used as binders. By the variation of content and type of binder the various products with the different level of compressive strength were obtained.