Silica ratio

These ate the main reactions ia Pordand cements because the two calcium siHcates constitute about 75% of the cement. The average lime—silica ratio (C S) may vary from about 1.5 to about 2.0 or even higher, the average value is about 1.7. The water content varies with the ambient humidity, the three moles of water being estimated from measurements ia the dry state and stmctural considerations. As the lime—silica ratio of the C—S—H iacreases, the amount of water iacreases on an equimolar basis, ie, the lime goes iato the stmcture as calcium hydroxide, resulting ialess free calcium hydroxide. 

As there now exists a large body of laboratory studies on each of the variable systems, for example the effect of die lime/silica ratio in the slag on the desulphurization of liquid iron, the most appropriate phase compositions can be foreseen to some extent from these laboratory studies when attempting to optimize the complex indusuial process. The factorial uials are not therefore a shot in the dark , but should be designed to take into account die laboratory information. Any qualitative difference between die results of a factorial uial, and the expectations predicted from physico-chemical analysis might suggest the presence of a variable which is important, but which was not included in the nials. 

Fig. 4.16 Structural parameters of carbon nanocage materials as a function of the sucrose to silica ratio in their synthesis (A) pore diameter (B) specific surface area (C) specific pore volume.

F/g. The lime-silica ratio of hydration products of tricalcium silicate hydrating in the presence of 0 and 2% calcium chloride as a function of the degree of hydration (Odier). 

The final alteration product strongly depends on the phosphate/silica ratio in the contacting groundwaters. However, in the near field and because of the massive presence of bentonite, the supply of silica will be unlimited and, therefore, the final alteration will most probably be ... 

The structures of mesoporous molecular sieves were closely related to the surfactants to silica ratios.4 Because of the absence of high order reflections on the XRD patterns of all LZC... 

The way in which salts such as calcium chloride and calcium formate operate is not fully understood, but it is clear that the mechanism involves an acceleration of the C S and C S hydration. It has been proposed [23] that the initial products of cement hydration form a sort of membrane which acts as a restraint to the diffusion process which in turn leads to the dormancy period . It seems likely that the chloride ion, by virtue of its small size and high mobility, is able more easily to penetrate the pores of the restraining layer allowing the diffusion process to proceed more rapidly. The resultant tobermorite gel has a higher lime-silica ratio and a more open, accessible structure, based on a crumpled foil morphology rather than the usual spicular. The considerable reaction with,... 

Type III High-early-strength (HES) cements are made from raw materials with a lime-to-silica ratio higher than that of Type I cement and are ground finer than Type I cements. They contain a higher proportion of calcium silicate than regular portland cements. 

Fig. 20. a Scheme for using silica particles as stabilizer for monomer droplets of miniemul-sions(Pickering stabilization) b Represents a latex with a monomer to silica ratio of 1 0.32... 

AR = alumina ratio (alumina modulus). ASR = alkali silica reaction. LSF = lime saturation factor. SR = silica ratio (silica modulus). C, = analytical (total) concentration of x, irrespective of species, [x] = concentration of species x. x = activity of species x. RH = relative humidity. =... 

Lime saturation factor, silica ratio and alumina ratio... 

Model materials similar to the M41 family can be modeled using lattice MC simulation under the assumption of non silica polymerization conditions. The structures observed are in agreement with experimental evidence with respect to the surfactant/silica ratio, temperature and surfactant architecture. Even when the resulting structures have a strong influence of the lattice constraints, adsorption properties on such materials are in good agreement with experimental observations. Adsorption properties of modeled materials are similar to experimental observations on MCM-41 type materials and show heterogeneity at low pressures. Such behavior is not observed in smooth cylinders. 

The morphology of zeolites can also be strongly influenced by the variation in different synthesis parameters. Aluminium content, template/silica ratio, water content, nature of cations present, alkalinity and degree of polymerization of the silica are all major factors which can influence the crystallization and hence the morphology of zeolites [5 - 7]. These particle morphological types can generally be characterized as either spherulitic (polycrystalline spherical) or lath-shaped (polyhedral) in nature. In both cases... 

The data obtained were plotted as viscosity versus temperature for the different materials and displayed the expected exponential increase in viscosity as the temperature decreased. For most of the slags a characteristic sudden increase in viscosity was noted, as in some related studies (J 3 ). Some typical results are shown and compared with the Watt-Fereday and modified silica ratio projections, assuming only a liquid phase exists, in Figures 1 and 2 (slags 1 12). 

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