EFFECTS OF ADDITIVES ON GYPSUM SLURRY BEHAVIOUR

The implementation of this study is based on methodology, exploring opportunities for adding of inorganic mineral additives in suspension of β-hemihydrate form obtained from desulfo-gypsum. The main purpose as to study the changes in gypsum slurry behaviour by incorporating three rates (5%, 15% and 25%) of Na-feldspar, dolomite and waste marble powder as substitutions of hemihydrate material. The research framework includes tests based on standards for gypsum based building materials. These incorporates analyzes of physical and chemical properties of the raw materials, examination of prepared gypsum slurries and tests on the set composite samples. All types of mineral additives included at gypsum mixture recipe have different morphological characteristics and physicochemical properties, which impact in diverse ways of prepared gypsum bodies. The results obtained show that the difference in structure, origin and chemical composition of minerals additives determines the behaviour of prepared gypsum slurries and the properties of set gypsum bodies

UTILIZATION OF CONSTRUCTION WASTE AS RAW MATERIAL IN MANUFACTURING OF GYPSUM-BASED COMPOSITES

This paper presents a laboratory investigation of new application opportunity of building waste materials and potential usage as a component in production of gypsum based building materials. Production of new type eco-friendly gypsum based composites was studied as a potential utilisation sector. The main focus is directed on gypsum binder mixture properties examination with different proportion of incorporated construction waste materials 5-45%. It was designed and tested fresh state behaviour of gypsum-waste mixture and specimens in standard water/binder ratio. Construction waste material is a fines obtained by combined crushing-sorting installations. Slump flow test of gypsum-waste suspension and dry samples characteristics as compressive and flexural strength, water absorption and shrinkage were tested. On the basis of the obtained results, it was established that the prepared gypsum-waste mixture is an alternative for the production of gypsum based building products. Using the tested mixture in manufacturing processes lead to reduction in the energy and water consumption