The effect of sodium aluminate on the properties of the composite cements

Abstract

The effect of sodium aluminate activator on properties of the Portland-composite cement (clinker factor 65 %) was studied and the results are being discussed. It is shown that the introduction of sodium aluminate (Na[Al(OH)4]) leads to an increase in the water demand of cement and a decrease in its strength. The results showed that the sodium aluminate and polycarboxylate ether (PCE) admixtures ensure the production of higher strength cements. It has been found that the addition of Na[Al(OH)4] – PCE significantly increases the compressive strength of cement mortar, particularly at 10–48 h of hydration. XRD and SEM measurements confirm that the hydration of composite cement with the addition of Na[Al(OH)4] – PCE is greatly accelerated by the way of formation of intense lines ettringite. It has been shown that the introduction of a sodium aluminate into the cement mortars allows to accelerate hardening and increase early strength and using of composite cement will provide improved performance and suitability. The results have shown that alkaline accelerator and polycarboxylate were effective for decrease shrinkage of composite cements.

Effect of layered double hydroxides Ca-Al LDHs and polycarboxylate ethers on the hardening of Portland limestone cement

“…This makes it possible to advance research into the system "cement-accelerator Na[Al(OH) 4 ]", which coincides with the results reported in [7,8]. However, the difference in terms of the results from [10] is to identify the processes of formation of hexagonal phases of type C 4 AN 19 , which contribute to the rapid growth of the early strength of cement stone due to the action of this accelerator. This indicates the expediency of further advancement of research into this area.…”

“…This will make it possible to obtain extra rapid-hardening modified Portland limestone cements for repair mixtures and increase their operational properties and durability. AF m -phases in the early period of Portland cement hardening [9,10]. This approach is relevant and provides significant prospects in the design of new compositions of repair mixtures.…”

Mitigation of Corrosion Initiated by Cl− and SO42−-ions in Blast Furnace Cement Concrete Mixed with Sea Water

“…The most known ways to activate latent hydraulic properties of the GGBFS is to apply calcium [10] and sulfate activators [11]. It is also known that low alkaline [12] and nearly Materials 2022, 15, 3003 2 of 18 neutral salts [13] can be used as activators of blast furnace cements as well. Na (K) salts of strong acids also ensure the increased hydraulic activity of the GGBFS [14].…”

Study on the Influence of Alkali Activator Solutions on Strength Improvement of Pozzolan Calcium Hydroxide Binders

“…The binders made from pozzolan and calcium hydroxide which have been activated by alkali solution both products C-(A)-S-H and N(K)-A-S-H might co-exist (Davidovits, 2017). But also there might be intermixing of the gels due to modification process taking place within the systems leading to a partial or total replacement of sodium with calcium to form a giant geopolymer chain (N,C)-A-S-H gels (Kropyvnytska et al, 2019).…”