This test is about setting time of Hydraulic Cement by Vicat Needle

1. Koya University
Faculty of Engineering
Civil Department - 2nd Stage
Concrete Technology
Test no: 3
Time of Setting of Hydraulic Cement by Vicat Needle
Student Name: Muhammad Saleem Asaad
Group: B
Expr Date:29-11-2015
Submission Date: 13-12-2015

2. Introduction
This test method is performed to determine the setting time of
hydraulic cement by mean of manually operated standard Vicat
apparatus.
The test is carried out to find whether cement sets at a rate suitable
for a particular work or not. There is no necessary relationship
between the time of setting and that of hardening or attaining the
maximum strength. Slow setting cement may harden more rapidly
than a quick setting one, and vice versa. The hardening of cement is
actually a continuation of the chemical action which began with
setting if the cement is placed in the mould. After initial setting time
the cement mould can be detached and after final setting time the
Vicatt’s apparatus plunger gives no impression.
The initial setting time can be defined as “time taken by paste to
stiffen to such an extent that the Vicatt’s needle is not permitted to
move down through the paste more than 25 mm.”
The final setting time can be defined as “it is the time after which the
paste becomes so hard that Vicatt’s 5mm needle doesn’t sinks visibly
and leave no impression”.
With Portland cement and rapid hardening cement the normal initial
setting time should not be less than 30 minutes and the final setting time
should not be more than 10 hours. With quick setting cement the initial
setting time should not be less than 5 minutes and the final setting time
should not be more than 30 minutes.

3. Apparatus
1. Vicat apparatus: It consists of a frame, bearing a movable rod,
weighing 300±0.5g, and having either:
• A removable needle, 1mm in diameter, for finding out the initial
setting time, or
• A needle, 5mm in diameter for determining the final setting time.
2. Conical hard rubber ring having 40 ± 1 mm height, inside diameter
at the bottom of 70 ± 3 mm and inside diameter at the top of 60 ± 3 mm.
3. Sensitive Balance.
4. Paste mixer.
5. Graduated glass cylinder.
6. Glass plate with adequate dimension.
7. Small trowel.
8. Stopwatch.

4. Test Procedure
Weight out 500g of cement and place it on the mixing plate.
Form a crater in the center and add a measured quantity of water
(the percentage of water obtained from normal consistency test).
Turn the material at the outer edge into the center within 30 sec.
of time by the aid of the trowel.
After an additional interval of 30 sec. for absorption of water,
complete the process by continuous vigorous mixing. Squeeze and
kneading with hands for (1.5 min.).
With the hands quickly form this paste into a ball, complete the
process by tossing the ball six times from one hand to the other hand,
keeping the hands about 6 in. (15 cm) apart.
Press the ball, resting in the palm of one hand, into the large end
of the conical ring of Vicat apparatus which held by the other hand.
Fill up the conical ring and remove the excess at the large end by
a single movement of the palm of the hand.
Place the ring on its large end on a glass plate and slice off excess
paste at the smaller end at the top of the ring by single oblique stroke
of a sharp edged trowel held at a slight angle with the top of the ring,
and smooth the top if necessary, but never compress the paste during
these operations.
Place the ring with the paste under the rod of the Vicat apparatus,
bring the initial setting needle (1mm) in contact with the surface of
the paste, and set the scale to read zero or read the initial reading.
This must not exceed 30 seconds after completion of mixing.
Release the plunger immediately and allow the needle to settle
for 30 s. Determine the penetration of the 1-mm needle every 15 min
until a penetration of 25 mm or less is obtained (Make each

5. penetration test at least 5 mm away from any previous penetration
and at least 10 mm away from the inner side of the mold).
Record the results of all penetration tests and, by interpolation,
determine the time when a penetration of 25 mm is obtained. The
elapsed time between the initial contact of cement with water and the
penetration of 25 mm is the Vicat time of setting or Vicat initial time
of setting.
Set the (5 mm) diameter needle on the lower end of the rod.
Determine the Vicat final time of setting end point to be the first
penetration measurement
that does not mark the specimen surface with a complete circular
impression.
The elapsed time between the initial contact of cement and water
and the end point determination above is the Vicat final time of
setting.

6. Calculation of Initial Setting Time
[(
𝐇−𝐄
𝐂−𝐃
)*(𝐶−25)] +𝐸
Where;
E = time in minutes of last penetration greater than 25 mm,
H = time in minutes of first penetration less than 25 mm,
C = penetration reading at time E, and
D = penetration reading at time H.
[(
𝟗𝟎−𝟕𝟓
𝟑𝟎−𝟐𝟎
)*(30−25)] +75 = 82.5



ASTM C150-07 Specification
For all types of Portland cement (I, IA, II, IIA, III, IIIA, IV & V):
• Initial time of setting, not less than 45 min.
• Final time of setting, not more than 375 min.


Iraqi Specification 1984
• Initial time of setting, not less than 45 min.
• Final time of setting, not more than 10 hrs.

7. Figure 1: Vicat Apparatus for Initial & Final Setting Time

8. Discussion
Initial setting time is that time period between the time
water is added to cement and time at which 1 mm needle
fails to penetrate the cement paste about 25 mm, by this
test we know the time that cement taken to set initial. Our
initial setting time equal 82.5 and according to Iraqi
specification because not less than 45 min, during this test
we have some factors that affect on the result if weather
not good or the needle during needle penetration not
clean in the result if Initial setting time not qualified we
can’t use it in engineering.