Determination of parameters of dry building mixtures based on gypsum and polymer additives for finishing works

The properties study of raw materials and dry building mixtures based on gypsum was carried out in accordance with the current regulatory documents of Ukraine. In the course of laboratory studies, the rheological and physico-mechanical properties of construction gypsum from two quarries were determined. The fundamental difference between these two types of materials was determined and the expediency of using each of them was justified both from the point of view of quality and availability of each of the materials. A number of studies of multi-component building compositions have been carried out, both in terms of rheological and physical-mechanical properties of the finished coating without the use of additives-modifiers (composite system "binder ‑ aggregate"). The interaction of two binder types with two types of inert fillers of natural origin (chalk, limestone) separately or their combination was considered. Modifier additives were considered as components that have an impact on the required properties of the finished material. Additives-modifiers are considered depending on the spectrum of their action, conclusions are drawn regarding the expediency of their use, the conditions under which they are necessary components of the composite system are determined. The most rational dosage of components that influence on the properties of the working mixture and the finished coating is provided. Laboratory studies of the product’s properties of the most well-known manufacturers of gypsum-based dry construction mixtures, which are used by Ukrainian consumers (produced in Ukraine and Turkey), were conducted. The research results are presented and a comparative analysis of the obtained results is made. Information is given on the quality of raw materials used by these manufacturers. The main parameters of the technology for performing internal furnishing works with the use of building mixtures based on gypsum and polymer additives according to all technological operations during manual and machine application of gypsum coating are determined. The fundamental points related to the smoothness of strength gain of the finished building composition have been determined. Recommendations for the use of regulators of the process of gaining the strength of materials based on building gypsum are presented.