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.

No abstract

The results of comparative studies of geopolymer concrete strength made with coarse aggregate based on granite, limestone, concrete scrap were given. It is found that the use of granite aggregate instead of limestone and concrete scrap reduces the strength flexural 2-2.5 times, as on impact - 2.5-3.5 times; the compressive strength decreases by 10-30%. It concluded that the main item that reduces the strength of the investigated geopolymer concrete when using granite aggregate, its low creep is observed, which, with high autogenous shrinkage of the geopolymer binder, leads to concrete cracking. The established features of the influence of the type of aggregate on the properties of concrete substantiate the use of crushed limestone and concrete scrap as a coarse aggregate of geopolymer concrete.

The influence of the milled opoka of Penza field and blast-furnace slag with the polycarboxylate superplasticizer present on the properties of mortar component of the concrete based on blended cement, including Portland cement, fly ash, blast-furnace slag, silica fume, and microquartz has been investigated. Some equations for the dependency of water requirement of the cement mortar component, as well as of its strength with various values of time on proportion of superplasticizer and components of blended binder have been developed. It has been shown that the introduction of opoka increases the water requirement of the mix, insignificantly decreasing the strength, when proportioned up to 15%. The detrimental effect of opoka on the strength considerably reduces with higher superplasticizer content and lower water-to-cement ratio.

No abstract