DETERMINATION OF

NORMAL CONSISTENCY OF HYDRAULIC CEMENT

I. OBJECTIVES

This experimental work is intended to determine normal consistency of

hydraulic cement in order to know the initial setting time (determining

volume of water needed to prepare hydraulic cement past).

II. TOOLS AND EQUIPMENT

1. Mixer, with some leaves mixers that are made out of stainless steel

and removable bowl

2. Vicat cement (using the end of C as shown in the picture A.2

3. Scale with 1.0 gram of sensitivity

4. Scraper that is made out of stiff rubber

5. Measuring cup (capacity 150 or 200 mL)

6. Trowel

7. Rubber gloves

III. MATERIAL

1. Portland cement ± 3.5 kg (for approximately six experiments)

2. Clean water (room temperature)

IV. PROCEDURE

Hydraulic cement past

1. Set the leave, mixer, and its bowl.

2. Fill all the materials into the bowl and mix as follows:

a. Pour water (±155-125 cc for Cement Type I and ±130 – 140 cc

for Cement Type II).

b. Pour 500 grams of cement into the water; let the absorption

occur for approximately 30 seconds.

3. Turn the mixer on, use the 140±5 rpm and mix the paste around for

around 30 seconds.

4. Turn the mixer off during 15 seconds and sweep the paste on the

inner part of bowl

5. Turn the mixer on with normal speed rotation (285±10 rpm) and

mix the paste for 1 minute.

Testing with vicat tool

1. take the paste from the bowl and form a ball. Throw the cement

paste ball from one hand to another at around 15 cm of distance

several times. Place it into a vicat tool (see Figure A.2). Push it into

the conic ring (G) therefore it fills properly into the ring.

2. Place the ring to a plate of glass (H) and pour the rest of the cement

paste into the ring from two directions. Equalize the cement paste

using spatula but do not push the cement paste.

3. Place the ring containing cement paste under the shaft (B) so that

the needle of the vicat tool can contact/touch the surface of the

cement paste. Lock the shaft by turning the key (K).

4. Place the indicator (F) precisely to zero point (upper layer). By

turning the key (K) open, we release the shaft (B), and at the same

time needle (C) will penetrate into the cement pate.

5. If in thirty seconds the depth of needle © is around 10±1 mm from

the surface, the consistency of cement paste is normal.

6. If the normal consistency is unreached, repeat step 1 until 1 so that

the condition is reached.

7. Record the volume of water that was used to reach normal

consistency.

8. Plot the (graph) relationship of the depth of needle penetration and

water content (in percentage) in cement paste

V. NOTE

VI. CALCULATIONS

Constant: 500 grams of cement

Depth of Needle

Penetration (mm)

Water Content (%)

24 23.07

9 20.00

24 918

19

20

21

22

23

24

Depth of Needle Penetration with Different Water Content

Water Content

Depth of Needle Penetration (mm)

Wat

er C

onte

nt (%

)

VII. EXPERIMENTAL ANALYSIS

1. Analysis of the Experiment:

In order to start testing with the vicat tool, we first needed to make

several samples of cement paste. We gathered the leave, mixer,

and a bowl. We then poured water and 500 grams of cement into

the water, leaving 30 seconds for water absorption, before mixing

using a speed of 140 ± 5 rpm for 30 seconds. We the turn off the

mixer, sweep the paste off the inner part of the bowl to ensure an

even mixture, and then turned the mixer on with a rotational speed

of 285 ± 10 rpm for one minute.

After the sample of cement paste was ready, we took the entire

sample and made it into a ball. We then threw the cement paste

ball back and forth between each hand, with a distance of 15 cm,

for several times, before placing inside the conic ring of the vicat

tool. Afterwards, we placed the ring onto a plate a glass and poured

the remaining amount of cement paste into the ring from two

directions. We also made sure that the surface of the conic ring is

smooth, without compressing the cement paste. After these

preparations were completed, we placed the needle of the vicat tool

just so it barely contacts the surface of the cement paste and then

locked the shaft. Afterwards, we placed the indicator to the zero

point and released the shaft, causing the needle to penetrate the

cement. After thirty seconds, we measure the depth of the needle. If

the depth is not around 10 ± 1 mm from the surface, we repeat the

experiment using different water contents.

2. Analysis of the Results:

It was necessary to repeat this experiment once. In the first text, we

used 500 grams of cement and 150 grams of water. This means

that the resultant cement paste had a weight of 650 grams and a

water content of 23.07%. However, the consistency of this cement

paste was not considered normal. With this cement paste, the

needle penetrated, within 30 seconds, to the depth of 24 mm, which

is greater than the normal consistency by 240%.

With the first result having a very high depth of needle penetration,

we reduced the water content of the cement paste in the second

test. The result cement paste had 500 grams of cement and 125

grams of water. This means that the cement paste now possessed a

weight of 625 grams and a water content of 20%. After testing with

the vicat tool, we gained a depth of needle penetration of 9 mm,

after thirty seconds. As this depth of needle penetration is within

the acceptable limits of 10 ± 1 mm, it was determined that this

mixture of cement and water possesses the normal consistency of

hydraulic cement paste.

3. Error Analysis:

During the multiple weightings to obtain the constant weight of

cement and the needed weight of water for each cement paste

sample, an offset error may occur due to improper reading of the

scale. Additionally, as the scale has a random error of .1%, the

weight of each sample of aggregates may not be completely

accurate. An error may also occur during the uniform distribution of

the top of each cement paste sample in the conic ring. Finally, an

error may also occur from reading the indicator of the vicat tool.

However, all these errors are extremely minor, and do not have a

significant effect on the results of this experiment.

VIII. CONCLUSIONS

Overall, the purpose of this experiment is to determine the normal

consistency of hydraulic dement in order to know its initial setting

time. This is done by determining the volume of water needed to

prepare hydraulic cement paste. In the end, the result is that in order

to obtain the normal consistency of hydraulic cement paste, a water

content of 20% is required.

IX. REFERENCES

American Society for Testing and materials. “Standards Test method

for Normal Consistency of Hydraulic Cement”, No. ASTM C 187 – 98

(Reapproved 2003). Annual Book of ASTM Standards, Vol. 04. 01.

X. APPENDIX

PROPERTIES OF MATERIALS EXPERIMENTAL REPORT

DETERMINATION OF NORMAL CONSISTENCY OF HYDRAULIC CEMENT

MODULE A.2

GROUP 29

Fajar Surya Muhammad 1306437170

Muhammad Alif Maggalatta 1306388906

Raihan Alisha Nabila 1306437126

R.A Tamara R F Iskandar 1306388894

Zain Zahran Azzaino 1306437044

Date of Experimental : October 30th 2013

Experimental Assistant : Putri Marastuti

Date of Approval :

Score :

Assistant’s Signature :

LABORATORY OF STRUCTURE AND MATERIAL

CIVIL ENGINEERING DEPARTEMENT

ENGINEERING FACULTY

UNIVERSITY OF INDONESIA