An arbitrary division has been made for the setting time of cement as the initial setting time and final setting time. Vicat’s apparatus is used for setting times also.
1. Initial Setting Time
About 500 g of the cement sample is taken and water content 0.85 P, where P is the percentage of water required as per the consistency test is added and made into a paste. The paste has to be made within a period of 3–5 minutes and filled into the mould.
For this test, a needle of 1 mm square size (needle C) is used. The needle is allowed to penetrate into the paste. The time taken to penetrate 33–35 mm depth is taken as the initial setting time.
2. Final Setting Time
The needle C is replaced by needle F. The attachment is lowered gently to cover the surface of the test block. The central needle makes an impression, whereas the circular cutting edge fails to do so. That is, the paste has attained hardness, and the centre needle does not penetrate the paste more than 0.5 mm. Thus, the time at which the needle does not penetrate more than 0.5 mm is considered to be the final setting time.
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