Initial & Final Setting Time of Cement Test
Initial & Final Setting Time of Cement
Initial & Final Setting Time of Cement test is used to detect the deterioration of cement due to storage.This is a conventional type of cement test and it has no relation with that of hardening of concrete.
Initial Setting Time of Cement Test Procedure:
1. Take 300 gm of cement and mix it with water percentage as mentioned in consistency test of cement
2. Now the prepared cement paste is filled in the vicat mould.
3. The square needle of cross-section 1 mm x 1 mm is attached to the movable rod of the Vicat apparatus.
4. Then the needle is allowed to quickly release and allowed to penetrate in the cement paste. In initial stage, the needle penetrates completely. It is then taken out and dropped at a fresh place. The test procedure is repeated at regular intervals till the needle does not penetrate completely. The needle should penetrate upto about 5 mm measured from bottom.
5. The initial setting time is found out by taking the interval between the addition of water to cement and the stage when needle stops to penetrate completely. The time should be about 30 minutes for ordinary cement.
Final Setting Time of Cement Test Procedure:
1. The initial test procedure is same that of initial setting time test.
2. Instead of square needle, annular collar is used. The annular collar is attached to the movable rod of vicat apparatus.
3. The annular rod is gently released. The time at which the annular rod makes an impression on test block and the collar fails to do so is noted.
4. The final setting time is found out by taking the difference between the time at which water is added to cement and time as recorded in.
5. The final setting time for ordinary cement should be 10 hours.