Ground granulated blastfurnace slag

Table 9.2 Atom ratios in a typical ground granulated blastfurnace slag...

First of all the C/S molar ratio changes depending on the saturation of the liquid phase in concrete, in relation to Ca(OH)2 (Fig. 3.17). Especially in the case of cements with mineral additions, particularly siliceous fly ash or ground granulated blastfurnace slag, this ratio decreases and the sections of chains composed of [SiO ] " tetrahedra become longer [32]. 

Fig. 3.20 C-S-H honeycomb constitution in the pastes produced from the ground granulated blastfurnace slag activated with NUjSiOj, the cracked slag grain is visible. (By the courtesy of B. Trybalska)...

The other fine powder components, added to control the workability of concrete mixture are fly ash, limestone flour and ground granulated blastfurnace slag. The content of these mineral additions can be substantially high when cement type CEM 1 is used they substitute up to 50% cement, particularly that of class 42.5. One can conclude that the Portland cements with mineral additions can be also applied. The effect of limestone flour on the properties of concrete mixture was studied, among the others, by Gizeszczyk [32],... 

Madrid, J. et al. (1997) Durability of ordinary Portland cement and ground granulated blastfurnace slag cement in acid medium, ia Proceedings 10th ICCC, Gdteborg, paper 4iv040. 

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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