Influence of silica-containing additives on strength properties of lightweight concrete on porous aggregate

The effect of silica-containing additives, obtained by leaching waste magnesium-iron slag from copper-nickel production, on the strength properties of lightweight concrete on porous aggregate has been studied. It has been established that the introduction of SiO2 additives in the amount of 0,5–2,0 wt. % into the composition of concrete increases the strength of concrete at the design age by 15–40 % compared to the composition without additives. The additives also increase the specific strength of concrete up to 38–40 MPa, which makes it possible to classify the developed concretes as high-strength ones (Rud ≥ 25 MPa).