DefinePK

Abstract

Efficient and rational use of ash and slag waste from a thermal power plant for the production of building binders is primarily determined by their quality properties, as well as the technology used and its optimal parameters. This article is devoted to solving these issues. The results obtained showed that ash and slag from the TPP of SSGPO JSC (Rudny, Kazakhstan) are effective materials for obtaining slowly hardening and cement-containing binders from them, used for the construction of the bases of road pavements. To study the physical and mechanical properties of binders, samples of 10x10x10 cm were made, hardened for 28 days under normal conditions. It has been established that the cement-ash-and-slag binder with the addition of 20 to 50% ash and slag has an activity of 25-37 MPa, and in terms of efficiency, as a binder, it surpasses the slowly hardening ash-and-slag binder. On the basis of a cement-ash and slag binder, it is possible to make a concrete mixture for the construction of the bases of road pavements of any category (the ratio between SHGPS: TsZShV can be 1: 5; 1: 4; 1: 3; 1: 2; and 1: 1). In this case, the strength of the bases can vary from 2.8 ... 14 MPa (for a mixture of 1: 5 composition) to 9 ... 17 MPa (for a mixture of 1: 1 composition). To determine the optimal parameters of the developed technology for producing a cement - ash and slag binder, a methodical approach based on probabilistic-deterministic planning of the experiment was used. In accordance with the plan of the experiment, 16 laboratory experiments were carried out to obtain cement-ash-and-slag binders, for each of which the mobility of the cement-ash and slag test was determined. From the obtained binders of various compositions, samples-beams with a size of 4x4x16 cm were also made, which, after holding for 28 days under normal conditions, were tested for bending and compression. It has been established that the optimum technology indicators are achieved when the cement content in the ash-and-slag mixture is 50%, the mixing time of the dry mixture is 9 minutes, the water-binding ratio is 0.35, and the mixing time of the wet mixture is 5 minutes. At the same time, the binder of optimal composition has sufficient strength after 28 days of hardening, allows to reduce cement consumption and provides increased homogeneity and mobility of mixtures in dry and wet state, which facilitates technological processes for preparing hardening systems (bending strength - 4.7 MPa; compressive strength - 34.4 MPa and the mobility of the cement-ash and slag test is 4.5 cm).