Hardening Kinetics of Geopolymer Binder Based on Magmatic Rock with Mineral Additives

Abstract

The influence of various factors on the hardening kinetics of composite geopolymer binders based on the milled waste of magmatic rock production and processing has been investigated. The type and dosage of the binder mineral additives - granulated blast-furnace slag and fly ash - as well as the composition of the hardening activator, component dispersion, and hardening temperature have been studied as the factors determining the rate of strength development. Some analytical dependencies describing the influence of the examined factors on the strength of geopolymer magmatic rock-based binders have been developed. The dependencies developed were used to establish the requirements for process conditions of the geopolymer construction products and structures production.

Improving the Properties of Porous Geopolymers Based on TPP Ash and Slag Waste by Adjusting Their Chemical Composition

“…These elements are able to form two- and three-dimensional structures. During synthesis, silicon and aluminum atoms form strong, branched Si–O–Al–O chains, due to which geopolymers are not inferior in physical and mechanical properties to rocks [ 21 ].…”

“…[ 19 ]. In view of the high content of aluminosilicate amorphous phase in the composition of ash and slag and their high dispersion, the method of processing ash and slag into geopolymers, which are a new class of materials that are hydraulic binders of alkaline activation, is promising [ 20 , 21 , 22 ]. They are glass–crystalline aluminosilicates consisting of [SiO 4 ] and [AlO 4 ] tetrahedra connected in series by bridging oxygen.…”

Analytical Review of Geopolymer Concrete: Retrospective and Current Issues

“…Of the entire set of geopolymer binder systems, one of the most studied mechanisms of structure formation are systems based on GGBS. The Si–O–Si and Al–O–Si compounds in the medium of a highly concentrated mortar undergo destruction and pass into a colloidal state; then, with an increase in the number of colloidal particles, they are compacted and strengthened [ 60 , 61 ]. Thus, the hydration products of the GGBS-based geopolymer binder are calcium hydrosilicates and sodium hydroaluminosilicates.…”

“…At the seventh stage in Figure 9 h, the polycondensation of the albite structure of the sodium polysilicate-disiloxo continues with the formation of typical feldspar chain structures [ 60 , 61 ].…”

“…The mechanism of chemical reactions that take place during structure formation is the basis for the study of geopolymer materials, in particular, their properties, structure formation features, types of alkaline binders and mixture formulations. In conjunction with the fact that the scope of geopolymer concretes, their structure and properties depend on the Si/Al ratio [ 60 , 61 ], understanding the essence and processes of geopolymerization, as well as knowledge of the mechanism of chemical reactions occurring in this case is the most important aspect in designing geopolymer materials, products and structures from them, as well as creating new composites.…”