Slag blastfurnace granulated hydration

The granulated blastfurnace slag and siliceous fly ash addition will have a similar effect on the ability of chloride ions binding in cement pastes, because they will also decrease the C/S ratio in C-S-H gel. Uchikawa and Okamura [210] report the following C/S ratio 1.7 for Portland cement, 1.6 in case of 40% slag addition and 1.2 at 40% of sihceous fly ash addition. Simultaneously, these additions will cause the aluminates content decrease in favor of calcium silicate hydrates. 

Granulated blastfurnace slag can hydrate without activation too [2]. The calcinm hydroxide necessary to activate the reaction of slag glass is probably formed as a result of calcium sulphide hydrolysis ... 

Partial replacement of Portland cement by natural or artificial pozzolans reduces the heat of hydration and also the unit price of concrete it slows down the process of hardening and the early strength is lower. Nevertheless, the majority of the volume of structural concrete used in technically advanced regions of the world are based on rational compositions of Portland cement and so called secondary binding materials fly ash, ground granulated blastfurnace slag, metakaolin, SF, and others. 

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