Scientific, technological, organizational and technical aspects of the production of building materials based on steelmaking slags

Introduction. This article presents research work on the further development of the technology of accelerated carbonation of steelmaking slags in the direction of manufacturing full-scale samples of building products (building bricks, paving slabs). Aim. Obtain products with physics-mechanical characteristics that are not conceding to small-piece road construction products (tiles, bricks) without the use of binders and other types of slag activation (grinding, introduction of alkalis, etc.), having a system of three components: steelmaking slag, water and carbon dioxide (CO2). Materials and methods. Steelmaking slag of PJSC NLMK with fractions up to 10 mm and gaseous carbon dioxide in a gas bottle in accordance with State Standard 8050-85 were used in the work. The influence of the following technological factors affecting the physical and mechanical characteristics of the obtained products has been studied: 1. In the process of molding products: granulometric composition of the mixture; humidity of the molding mixture; density of freshly molded products; pre-exposure and drying for reducing of humidity before carbonation. 2. In the process of accelerated carbonation: pressure, temperature, CO2 concentration, carbonation time. Results. The possibility of obtaining of small-piece road construction products based on steelmaking slags by hyperpressing using accelerated carbonation with strength characteristics that are not conceding to the requirements for small-piece road concretes has been experimentally proved. Conclusions. The possibility of manufacturing of highquality small-piece products without the use of binders and other types of slag activation (grinding, introduction of alkalis, etc.) has been proved. Technological patterns for obtaining products with the following characteristics have been established: compressive strength – 15–85 MPa, average density – 1700–2450 kg/m3, frost resistance – up to F2200.