Procedure for Test : Make a paste with 300 gms of cement with Pa percentage of water (which is of water required for normal consistency). The paste is filled in the mould of Vicat’s apparatus. In this apparatus, attach the needle of square section to the Vicat rod. Lower the system so that the needle just touches the surface of the paste and gently release. If the needle pierces into the paste fully, again release the needle after a few seconds. This operation is repeated till the needle does not penetrate fully into the paste. The interval of time between this instant and the instant at which water was added to the cement is “Initial Setting Time”
Now change the needle to the third one which has a projecting sharp point at the centre with an annular attachment. Release the needle as before on the same paste. The needle as well as the attachment will make their impressions on the paste. Repeat this process tll only the needle makes the impression but not the attachment. The interval of time between this instant and the instant at which the water was added is called the final setting time.
