BEAD FILLERS - POROURITES FOR CONCRETE FROM WASTES OF THE MINING ENTERPRISES OF KRYVIY RIH

Abstract

Reducing the raw material base is one of the main problems of the construction materials industry. In the Kryviy Rih iron ore basin, poor iron ores are used by enrichment, which gives a large amount of waste that is stored in quantity of millions cubic meters. Wastes worsen the environment in Kryviy Rih and can be considered as an artificially created raw material base for the manufacture of construction materials, including aggregates for concrete. The aim of this work is to obtain lightweight aggregates - porourites based on industrial wastes and to develop a method for their production. Standard and special methods were used to determine and study the properties of the components and the composition of the charge. To process the results of experiments, statistical analysis was used. When developing the composition of the mixture to obtain the raw granules of the porourite aggregate, the processes of crushing and mixing of raw materials and the influence of the size of the raw materials on the process of their manufacture were studied. Raw granules of artificial porous aggregate - porourite, consisting equally of silicate and shale industrial wastes, obtained with fineness of the latter less than 0.15 mm have the best performance. However, the process of manufacturing porourite granules satisfactorily proceeded at a fineness of 0.15 ... 1.15 mm. To increase the strength of raw granules with a 0.15 ... 1.15 mm shale size of technogenic raw materials, up to 2% of activated clay technogenic raw materials were added to the mixture, while their compressive strength reached 10.2 N / ok and impact strength of 5-6 times. An increase in the amount of shale technogenic raw materials with a particle size of 3 ... 1.5 mm adversely affects the strength of raw granules; therefore, their maximum allowable particle size was limited to 1.2 mm. For the production of granules of porourite aggregate, their rapid heating was chosen at a rate of temperature increase of 90 ... 95 ° C / min to the expansion temperature, since this made it possible to obtain their lowest density. The studies performed helped us to develop a method for the production of artificial porous aggregate for concrete - porourite from waste products of Kryviy Rih enterprises.