Concretes made of magnesium–silicate rocks

Abstract

At present, there is a shortage of high-quality feedstock to produce widely used building materials—concretes. Depletion of natural resources and growing restrictions on their extraction, in connection with environmental protection, necessitate the search for an equivalent replacement for conventional raw materials. Magnesium–silicate rocks are a waste of the mining industry. We researched the possibility of using these rocks as coarse and fine aggregates in heavy concrete production. Following the requirements of the national standards, we studied the physical and mechanical characteristics of the obtained material. It was found that the strength of concrete, made of magnesium–silicate rock coarse aggregate, at the age of 28 days of hardening is within 28 MPa, while the strength of the control sample is 27.3 MPa. Replacing quartz sand with dunite sand also leads to an increase in concrete strength (~4%). Complete replacement of aggregates facilitates an increase in strength by 15–20% than the control sample. At the same time, the density of the obtained materials becomes higher. Concretes have a dense structure that affects their quality. Concrete water absorption is within 6%. The fluxing coefficient is 0.85–0.87. The application of magnesium–silicate rocks in concrete production enables the complete replacement of conventional aggregates with mining waste without reducing the quality of the obtained materials. Furthermore, the issues of environmental protection in mineral deposit development are being addressed.