Self-compacting concrete with TPP fly ash

Abstract

The prospects and problems of multilevel optimization of the dispersed composition of self-compacting concrete are considered with the aim of significantly increasing its construction and technical properties, with a minimum content of binder. Theoretical and practical principles have been developed for the design of disperse-particle size distribution of self-compacting concrete mixtures for high-strength concrete, in which various types of dispersed mineral modifiers (MM) are used, including fly ash of thermal power plants (TPPs). Effective MMs for self-compacting concrete mixtures are varied granular blast furnace slag and fly ash of thermal power plants, which create a dense packing structure of particles of a multicomponent binder with a low degree of disorder and ensure a decrease in the consumption of Portland cement in concrete by 43-48%. With such a choice of the type and parameters of MM, self-compacting concrete mixtures are characterized by lower water content, high viscosity and a low level of ultimate shear stress, ensuring its high-quality compaction. To study the properties and structure of concrete, quartz sand with Mk −2.58 and granite crushed stone were used as a fine aggregate. 5-10 and 10-20mm, Portland cement of class CEM I 52.5N, finely dispersed blast furnace granulated slag, fly ash of thermal power plants. and Glenium 430 superplasticizer. Research methods: the shape and size of the dispersed particles of the components were determined by a laser analyzer, the mobility of the concrete mix according to GOST 10181-2014, the compressive strength of concrete according to GOST 10180-2012. The structure of the cement stone was studied by thermographic and x-ray phase analysis methods. The strength of concrete only from the use of fly ash from TPPs instead of the equivalent part of fine aggregate increases by 4.1−9.2%.