Experiment No 2
4
EXPERIMENT NO.2 TO DETERMINE THE INITIAL AND FINAL SETTING TIME OF CEMENT 1. EQPT/MATERIAL: Vicat apparatus with Initial set needle, Final set Attachment, Stop Watch, Portland cement, and Water. 2. PROCEDURE: a. Neat cement paste shall be formed by mixing cement with the quantity if water required giving a paste of standard consistence. b. Vicat mould shall be completely filled and the surface of the paste shall then be smoothed of level with the top of mould. While testing, temperature of material and the test room should 17.7 to 23.3ᵒC. c. For the determination of the initial setting time test block confined in the block/mould and resting on the plate shall be placed under the rod bearing needle. This shall then be lowered gently in contact with the surface of test block and quickly released and allow to sink in. This process shall be repeated until the needle, when brought contact with the test block and released as described above, does not penetrate beyond the point approx. 5± 1mm, from the bottom of the mould (34-35mm penetration from the top) d. The period elapsing between the points when the water is added to the cement the time at which needle ceased to pierce the test block is called the initial setting time.
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Transcript of Experiment No 2
EXPERIMENT NO.2
TO DETERMINE THE INITIAL AND FINAL SETTING TIME OF CEMENT
1. EQPT/MATERIAL:
Vicat apparatus with Initial set needle, Final set Attachment, Stop Watch, Portland cement, and Water.
2. PROCEDURE:
a. Neat cement paste shall be formed by mixing cement with the quantity if water required giving a paste of standard consistence.
b. Vicat mould shall be completely filled and the surface of the paste shall then be smoothed of level with the top of mould. While testing, temperature of material and the test room should 17.7 to 23.3ᵒC.
c. For the determination of the initial setting time test block confined in the block/mould and resting on the plate shall be placed under the rod bearing needle. This shall then be lowered gently in contact with the surface of test block and quickly released and allow to sink in. This process shall be repeated until the needle, when brought contact with the test block and released as described above, does not penetrate beyond the point approx. 5± 1mm, from the bottom of the mould (34-35mm penetration from the top)
d. The period elapsing between the points when the water is added to the cement the time at which needle ceased to pierce the test block is called the initial setting time.
e. For the determination of final setting time, same needle shall be used. The cement shall be considered as finally set when, upon applying gently to the surface of test block, only the needle makes and impression, while the attachment fails to do so.
f. If the scum is formed on the surface of test block, then underside of test block may be used for determining the final set.
3. PRECAUTIONS:
a. The needle should be allowed to touch the surface of cement in the cement paste.b. After every reading the needle should be cleaned.
4. DETAIL OF READINGS/OBSERVATIONS/DATA TO BE RECORDED/COLLECTED:
a. Type of cement.
b. Room temperature
c. Temperature of mixing water
d. Humidity
5. THE PERFORMA/FORMAT FOR PREPARATION OF RECORD OF OBSERVATION/DATA WITH NOTES TO HELP COMPLETION
S/NO. AMOUNT OF WATER (%)
PENETRATION(mm)
INITIAL SETTING TIME (min)
FINAL SETTING TIME(min)
1.
2.
3.
4.
5.
6. INTERPRETATION/COLLECTION OF OBSERVED READINGS , GRAPHS,ETC LEADING TO RESULTS
To be done with standard specification of ASTM Designation C150 and B.S 12:1978
7. COMMENTS:
