Silica modulus

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. =... 

The classic approach to the cement strength development was to increase the alite and CjA content, as well as the fineness of cement. The increase of silica modulus to about 3 and use of some minor components, mainly barium and boron results in further cement properties enhancement. The rate of hardening of these cements [121-123] is increasing with their specific surface in the range 4,400-4,600 cm /g and with K2SO addition (1.5 %), according to Grzymek s patent [124]. 

MGF-9/ waterglass ratio Initial silica modulus Modulus after mixing at given time ... 

A branched structure [128, 172] is supposed for sodium silicates characterized by silica modulus equal to 3 and more ... 

Composite structure investigations by optical microscopy have shown that increase in waterglass silica modulus leads to spherical particles enlarging due to the larger size of silicon-oxygen anions. 

Considerable changes in OMC organic and inorganic components, depending on the waterglass silica modulus, affect the physical, mechanical, chemical, and technological characteristics of the composites investigated. 

In the aging process of cured compositions, their compression strength noticeably increases, more so for compositions with lower waterglass silica modulus. For example, cured compositions with M = 1.35—2.35 after 15 days of aging increases 4—5 times, whereas the compositions with M = 2.35—3.0 show only 1.8—2 times growth of this index. The compression strength is reduced to a minimum with introduction of waterglass with M = 3.2. 

The influence of the waterglass silica modulus on physical and mechanical properties of organo-mineral composites is explained mainly by change in the composition of the products of reaction of... 

Figure 3.30 Compression strength (op) versus time for OMC containing waterglass with various values of silica modulus M (1) M = 1.35 (2) M = 1.64 (3) M = 2.35 (4) M = 3.2.

Compression strength increase in compositions with low-modulus waterglass is observed over 30 days. The rate of achieving maximum strength increases with silica modulus, but absolute values of this index are reduced considerably. For example, the maximum strength of cured composites with M = 3.2 is achieved in 2 days but is only IMPa, whereas for the composites with M = 1.35 the maximum strength is reached over 30 days but reaches 49 MPa. 

These are not the only limiting influences exerted hy the silica modulus on the viscous-elastic properties of OMC. An influence on the structure of the polycondensation products has also heen established [128-132]. Thus, silica modulus induces significant changes of the morphology and structure of both composite material phases, and the viscous-elastic behavior observed supports this. 

Low quantity of melt phases High silica modulus (Miller, 1980) silica ratio too high (Hofmanner, 1973)... 

Fortune, J ohansen, and Fimdal (1987) microscopically evaluated the effect of changing the kiln feed fineness from a normal value of 12% retained on the 90-pm sieve to 5-6%, with reductionin the silica modulus (MS) from 3.0 to 2.4. The results were an improvement in kiln fuel consumption, a much better clinker granulometry, smaller alite, and fewer belite nests. 

TABLE 3.33 Variations of Waterglass-MGF-9 Mixture Silica Modulus with Time... 

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