The balance between the silicate, aluminate and sulfate phases in cement is one of the most important aspects during hydration.In particular, a too low supply of sulfates results in an uncontrolled hydration of C3A that in turn retards silicates hydration.It appears that the use of comb-shaped polycarboxylate ether (PCE) superplasticizers can induce a noticeable perturbation of this balance, resulting in a strong retardation of hydration.