Hydratation of Ca 3 SiO5   Applications
Two main properties drive the industrial application of C3S
 a) its ability to reacts relatively quickly with water
b) its biocompatibility to the human tissue . The main reaction of hydration can be written:
Ca 3 SiO5   + H2O -à  C 1,5 SH + Ca(OH)2
C 1,5 SH is a nearly amorphous phase having the properties of a rigid gel. The  solid solution of Ca 3 SiO5( alite) is the most important constituent of all normal Portland cement clinkers of which it constitutes 50 -70%. and it plays a major role in the strength development at ages up to 28 days. figure 5 shows a SEM view of hydrated Ca 3 SiO5 ( CSH and Portlandite Ca(OH)2 )

Figure 5
Hydrated paste of Ca 3 SiO5 ( SEM)

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Pure Ca 3 SiO5 is the most important constituent of dental cement of which it constitutes 80% .It is devoted to root  filling. One of the most important  feature of Ca 3 SiO5 is the antimicrobial properties . Most bacteria present in the root canal system grow best at pH around 6,5 to 7,5 and at pH  more than 9 may reversibly or irreversibly inactivate cell membrane  enzymes of the microorganisme resulting a loss of biological activity.