INITIAL AND FINAL SETTING TIME

Updated: May 1, 2020

1.3 INITIAL AND FINAL SETTING TIME

AIM

To determine the initial and the final setting time of cement

as per IS: 4031 (Part 5) - 1988.

APPARATUS

i) Vicat apparatus conforming to IS: 5513 - 1976

ii) Balance, whose permissible variation at a load of 1000g

should be +1.0g

iii) Gauging trowel conforming to IS: 10086 - 1982

PROCEDURE

i) Prepare a cement paste by gauging the cement with 0.85

times the water required to give a paste of standard

consistency (see Para 1.2).

ii) Start a stop-watch, the moment water is added to the

cement.

iii) Fill the Vicat mould completely with the cement paste

gauged as above, the mould resting on a non-porous plate

and smooth off the surface of the paste making it level with

the top of the mould. The cement block thus prepared in the

mould is the test block.

A) INITIAL SETTING TIME

Place the test block under the rod bearing the needle.

Lower the needle gently in order to make contact with the

surface of the cement paste and release quickly, allowing it

to penetrate the test block. Repeat the procedure till the

needle fails to pierce the test block to a point 5.0 ± 0.5mm

measured from the bottom of the mould.

The time period elapsing between the time, water is added

to the cement and the time, the needle fails to pierce the

test block by 5.0 ± 0.5mm measured from the bottom of the

mould, is the initial setting time.

B) FINAL SETTING TIME

Replace the above needle by the one with an annular

attachment.

The cement should be considered as finally set when, upon

applying the needle gently to the surface of the test block,

the needle makes an impression therein, while the

attachment fails to do so. The period elapsing between the

time, water is added to the cement and the time, the needle

makes an impression on the surface of the test block, while

the attachment fails to do so, is the final setting time.

REPORTING OF RESULTS

The results of the initial and the final setting time should be

reported to the nearest five minutes.

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