Abstract
Ashes slag materials in the chemical and mineralogical composition are largely identical to natural mineral raw materials. They are a source of environmental pollution, pose a threat to public health, and a threat to the flora and fauna of the surrounding areas. Ashes slag waste contains a large amount of unburned fuel. In some ashes, the content of unburned fuel can reach 20-40%. In this case, it is advisable to use it as a raw material for the production of artificial porous aggregates. The paper presents the results of studies on the development of lightweight aggregate technology based on ashes slag with a high residual fuel content. To develop the technology of lightweight aggregate, ashes slag was used by Nova Zinc LLP (Karaganda region, Kazakhstan), in which the content of unburned coal is up to 75%. Based on ashes slag, lightweight aggregates were obtained using burning and non-burning technologies. By roasting (burning) technology, aggregates were obtained by burning at a temperature of 1000 and 1100 °C. The aggregates obtained have a bulk density of 395-687 kg/m3 and a compressive strength in the cylinder of 0.5-2.4 MPa. By non-burning technology Portland cement M400 was used as an astringent. After hardening, the aggregates have a bulk density of 400-600 kg/m3 and a 679 compressive strength of 0.65-1.5 MPa in the cylinder. Samples of light concrete with a density of 1200 and 1700 kg/m3, a compressive strength of 80 (B5) and 120 kg/cm2 (B7.5), and thermal conductivity coefficients of 0.43 and 0.67 W/mоС were obtained on the basis of the non-fired light aggregate, respectively. Lightweight aggregate and lightweight concrete in their functional properties meet the requirements of regulatory documents.