Dicalcium silicate doped

Matkovic, B. et al. (1986) Dicalcium silicate doped with phosphates, in Proceedings 8th ICCC, Rio de Janeiro, Vol. 2, pp. 276-280. 

Matkovic, B. and others, "Influence of BaSO on the Formation and Hydration Properties of Calcium Silicates, Parts I and II, Doped Dicalcium Silicates," Ceramic Bulletin, Vol. 60, Nos. 8 and 11,1981b, pp. 825-829 and 1164-1167. 

The reactivity and strength development of dicalcium silicate may be affected by the quality and quantity of the dopant. It is believed that the presence of dopants in the crystalline lattice generally increases the reactivity of dicalcium silicate by introducing defects or distorting the stracture of the crystalline lattice. However, there are only a few publications in the hterature in which the reactivity of the doped material is compared directly with that of non-doped C28. Table 3.2 summarizes data from experiments in which the reactivity of doped C2S was compared directly with that of a non-doped preparation produced in a similar way. For better comparison of different investigators data, the differences formd are expressed as a percentage of the value found in the control sample. 

In conclusion it may be stated that doping with appropriate foreign ions may help to increase the reactivity of dicalcium silicate however, such effects are rather limited, and generally the rate at which the doped material will react with water will remain below that of tricalcium silicate. The resultant reactivity will also depend on the amount of dopant used, and on the conditions of sample preparation. The rate of C2S hydration may be accelerated, to a limited extent, by adding suitable accelerators, such as CaCl2, Ca (N03)2, K2CO3 or calcium acetate (El-Didamony et al 1996). These act by forming insoluble compounds with Ca(OH)2 or catalytically. 

Another dopant that may be considered for increasing the reactivity of belite cements is S04 ions (Gies and Knofel, 1987 Stark et al, 1987). Under these conditions the final clinker contains the rather than the a -CjS phase, even if high cooling rates have been employed however, the SO -doped form of yff-dicalcium silicate is much more reactive than its SO -free counterpart. The doped C S typically contains about 3% each of SO3 and AI2O3 in its crystalline lattice. If an SO3-doped belitic clinker that also contains some alite is to be produced, the amoimt of SO3 in the raw meal must not exceed... 

Pr sh, R., Ahluwalia, S.C., and Sharma, J.M. (1992) Microstractural studies on pure and iron doped unhydrated and hydrated dicalcium silicate phase, in Proceedings 9th ICCC, New Delhi, Vol. 4, pp. 397-403. 

A form of jP-dicalcium silicate, -2Ca0.Si02 (abbreviation JP-C2S), doped with foreign ions. A regular constituent of Portland clinker. 

Crystallographic analysis of dicalcium silicates are conducted using DPT simulations to predict the hydraulic activity of pure p-Belite, as well as those doped with strontium or barium atoms. The results of this analysis are summarized as follows ... 

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