A method for determining the passivating properties of a mixture containing at least two components, which are cement and water, including the steps of: - taking a sensor comprising three elements, each made up of an electrically conductive material, these elements being referred to as first electrode, second electrode and third electrode, - fixing at least one of these three electrodes on a support in such a manner that • they are electrically insulated reciprocally, and • the mixture is able to come in contact with at least one predetermined face situated on the first electrode, second electrode and third electrode, these faces being referred to as first face, second face and third face, respectively, - selecting the first electrode and the third electrode and applying between these two electrodes, • a direct current, referred to as first direct current, of predetermined intensity value, referred to as first intensity value, and predetermined polarity, referred to as first polarity, resulting in electrolytic reactions on the third electrode, for a predetermined duration, referred to as first duration, and then - selecting the second electrode and the third electrode, and • measuring the voltage between these two electrodes during said first predetermined duration, and • storing the measurement for the variation of said voltage during said first predetermined duration, - comparing the variations in the voltage between the second electrode and the third electrode during the first predetermined duration, with predetermined data representing the variations in said voltage during said first predetermined duration for different pH values of the mixture, and - determining, based on the comparison, at least whether or not the mixture has such passivating properties. - taking a sensor comprising three elements, each made up of an electrically conductive material, these elements being referred to as first electrode, second electrode and third electrode, - fixing at least one of these three electrodes on a support in such a manner that • they are electrically insulated reciprocally, and • the mixture is able to come in contact with at least one predetermined face situated on the first electrode, second electrode and third electrode, these faces being referred to as first face, second face and third face, respectively, • they are electrically insulated reciprocally, and • the mixture is able to come in contact with at least one predetermined face situated on the first electrode, second electrode and third electrode, these faces being referred to as first face, second face and third face, respectively, - selecting the first electrode and the third electrode and applying between these two electrodes, • a direct current, referred to as first direct current, of predetermined intensity value, referred to as first intensity value, and predetermined polarity, referred to as first polarity, resulting in electrolytic reactions on the third electrode, for a predetermined duration, referred to as first duration, and then • a direct current, referred to as first direct current, of predetermined intensity value, referred to as first intensity value, and predetermined polarity, referred to as first polarity, resulting in electrolytic reactions on the third electrode, for a predetermined duration, referred to as first duration, and then - selecting the second electrode and the third electrode, and • measuring the voltage between these two electrodes during said first predetermined duration, and • storing the measurement for the variation of said voltage during said first predetermined duration, • measuring the voltage between these two electrodes during said first predetermined duration, and • storing the measurement for the variation of said voltage during said first predetermined duration, - comparing the variations in the voltage between the second electrode and the third electrode during the first predetermined duration, with predetermined data representing the variations in said voltage during said first predetermined duration for different pH values of the mixture, and - determining, based on the comparison, at least whether or not the mixture has such passivating properties.