Properties of Cement & its Test

2. Assignment
Name: Salman Hafeez
Roll No: 2kx5-Civil-106
Assignment: Cement, types of cement.
Submitted to: Engr. Adnan Shah

3. Cement
Definition:
“Cement is a crystalline compound of calcium silicates and other calcium
compounds having hydraulic properties” (Macfadyen, 2006).
 A cement is a binder, a substance used in construction that sets and hardens and can
bind other materials together. The most important types of cement are used as a
component in the production of mortar in masonry, and of concrete, which is a
combination of cement and an aggregate to form a strong building material.
 Cements used in construction can be characterized as being either hydraulic or non-
hydraulic, depending upon the ability of the cement to set in the presence of water.

4. Ingredients of Cement
Ingredient Percentage in cement
Lime 60-65
Silica 17-25
Alumina 3-8
Magnesia 1-3
Iron oxide 0.5-6
Calcium
Sulfate
0.1-0.5
Sulfur Trioxide 1-3
Alkaline 0-1
There are eight major ingredient of cement. The general percentage of these ingredients in cement is
given below:

5. Test of Cement
Testing of cement can be brought under two categories.
 Field testing
 Laboratory testing

6. Field Test of Cement
It is sufficient to subject the cement to field when it is used for minor works. The following are the field
test:
 Date of Manufacturing: As the strength of cement reduces with age, the date of manufacturing of
cement bags should be checked.
 Cement Color: The color of cement should be uniform. It should be typical cement color i.e. grey color
with a light greenish shade.
 Whether Hard Lumps are Formed: Cement should be free from hard lumps. Such lumps are formed by
the absorption of moisture from the atmosphere.
 Temperature Inside Cement Bag: If the hand is plunged into a bag of cement, it should be cool inside
the cement bag. If hydration reaction takes place inside the bag, it will become warm.

7. Field test of Cement
 Smoothness Test: When cement is touched or rubbed in between fingers, it should give smooth
feeling. If it felt rough, it indicates adulteration with sand.
 Water Sinking Test: If a small quantity of cement is thrown to the water, it should float some time
before finally sinking.
 Smell of Cement Paste: A thin paste of cement with water should feel sticky between the fingers. If
the cement contains too much pounded clay and silt as an adulterant, the paste will give an earthy
smell.
 Glass Plate Test: A thick paste of cement with water is made on a piece of glass plate and it is kept
under water for 24 hours. It should set and not crack.
 Block Test: A 25mm × 25mm × 200mm (1”×1”×8”) block of cement with water is made. The block is
then immersed under water for three days. After removing, it is supported 150mm apart and a weight
of 15kg uniformly placed over it. If it shows no sign of failure the cement is good.

8. If a sample of cement satisfies the above field tests it may be concluded that the cement is not bad.
The above test do not really indicate that the cement is really good for important works. For using
cement in important and major works it is incumbent on the part of the user to test the cement in
the laboratory to confirm the requirements of the Standard specification w.r.t its physical and
chemical properties. No doubt, such conformation will have been done at the factory laboratory
before the production comes out from the factory. But the cement may go bad during
transportation and storage prior to its use in works.

9. Laboratory test for Cement
The following test are usually conducted in the laboratory.
 Fineness test
 Setting time test (initial &final setting test)
 Strength test
 Soundness test
 Heat of Hydration test

10. Fineness Test
 Fineness of cement has a great effect on the rate of hydration and hence the rate of gain of
strength.
 Fineness of cement increases the rate of evolution of heat.
 Finer cement offers a great surface area for hydration and hence faster the development of
strength.
 Increase in fineness of cement also increases the drying shrinkage of concrete and hence creates
cracks in structures.
 Excessive fineness requirement increases cost of grinding.
 Excessive fine cement requires more water for hydration, resulting reduced strength and durability.
 Fineness of cement affects properties like gypsum requirement, workability of fresh concrete & long
term behavior of structure.
 Coarse cement particles settle down in concrete which causes bleeding.

11. Fineness test
Fineness of cement is tested in two ways.
a) By sieving
b) By Air Permeability Method

12. a) Sieve Test
 Weigh correctly 100 grams of cement and take it on a standard IS Sieve No. 9(90 microns).
 Break down the air-set lumps in the with the fingers.
 Continuously sieve the sample giving circular and vertical motion for a period of 15 minutes.
 Mathematical sieving device may also be used.
 Weigh the residue left on the sieve.
 This weigh shall not exceed 10% for ordinary cement .
 Sieve test is rarely used.

13. b) Air Permeability Method
Blaine’s air permeability apparatus consists essentially of a means of drawing a definite
quantity of air through a prepared bed of cement of definite porosity. The fineness is
expressed as a total surface area in square centimeters per gram.

14. Standard consistency
Standard consistency of cement may be defined as the percentage of water (by weight of
cement), to be mixed with the cement, to get a cement paste having some stiffness, which is
arbitrarily fixed with the help of Vicat apparatus.

15. Count. On Standard test

16. 1. Weight of cement (A) = 500 g.
2. Observations:
3. Weight of water in g for Standard consistency (B) =
 (Note: For standard consistency the depth of Penetration of vicat plunger should be 5 mm to 7 mm.)
4. Standard consistency in % (P) = B/A * 100=
S.No
.
Weight of water
(g)
Plunger
penetration
(mm)
1.
2.
3.
4.
5.
Calculation &Observation

17. Setting Time Test (Initial & Final setting time)
 Initial setting time is that time period between the time water is added to cement and
time at which 1 mm square section needle fails to penetrate the cement paste, placed in
the Vicat’s mould 5 mm to 7 mm from the bottom of the mould.
 Final setting time is that time period between the time water is added to cement and
the time at which 1 mm needle makes an impression on the paste in the mould but 5
mm attachment does not make any impression.

18. Setting time test
Test Block Preparation
 Before commencing setting time test, do the consistency test to obtain the water required to
give the paste normal consistency (P).
 Take 400 g of cement and prepare a neat cement paste with 0.85P of water by weight of
cement.
 Gauge time is kept between 3 to 5 minutes. Start the stop watch at the instant when the water
is added to the cement. Record this time (t1).
 Fill the Vicat mould, resting on a glass plate, with the cement paste gauged as above. Fill the
mould completely and smooth off the surface of the paste making it level with the top of the
mould. The cement block thus prepared is called test block.

19. Setting time test
Initial setting time test
 Place the test block confined in the mould and resting on the non-porous plate, under the rod bearing the needle.
 Lower the needle gently until it comes in contact with the surface of test block and quick release, allowing it to
penetrate into the test block.
 In the beginning the needle completely pierces the test block. Repeat this procedure i.e. quickly releasing the needle
after every 2 minutes till the needle fails to pierce the block for about 5 mm measured from the bottom of the mould.
Note this time (t2).
Final setting time test
 For determining the final setting time, replace the needle of the Vicat’s apparatus by the needle with an annular
attachment.
 The cement is considered finally set when upon applying the final setting needle gently to the surface of the test
block; the needle makes an impression thereon, while the attachment fails to do so. Record this time (t3).

20. Setting time test
Calculation
 Initial setting time=t2-t1
 Final setting time=t3-t1,
Where,
 t1=Time at which water is first added to cement
 t2=Time when needle fails to penetrate 5 mm to 7 mm from bottom of the mould
 t3=Time when the needle makes an impression but the attachment fails to do so.

21. Soundness Test
 Soundness is the ability of a hardened paste to retain its volume after setting.
 A cement is said to be unsound (i.e. having lack of soundness) if it is subjected to delayed destructive
expansion.
 Unsoundness of cement is due to presence of excessive amount of hard-burned free lime or
magnesia
 Unsoundness in cement is due to excess lime or excess magnesia in cement
 Unsoundness in cement due to excess lime is detected by the Lechatelier test.
 Unsoundness in cement due to excess magnesia & excess lime is detected by the Autoclave test

22. Soundness test

23. Soundness test
 The cement paste is prepared. The percentage of water is taken as determined in the Consistency
test.
 The mould is placed on a glass plate and it is filled by cement paste.
 It is covered at top by another glass plate. A small weight is placed at top and the whole assembly
is submerged in water for 24 hours. The temperature of water should be between 24°C to 35°C.
 The distance between the points of indicator is noted. The mould is again placed in water and heat
is applied in such a way that boiling point of water is reached in about 30 minutes. The boiling of
water is continued for one hour.
 The mould is removed from water and it is allowed to cool down.
 The distance between the points of indicator is again measured. The difference between the two
readings indicates the expansion of cement and it should not exceed 10 mm.

24. Heat of Hydration Test
 It is the quantity of heat (in joules) per gram of un-hydrated cement evolved upon
complete hydration at a given temperature.
 The heat of hydration can be determined by ASTM C 186 or by a conduction
calorimeter.
 The temperature at which hydration occurs greatly affects the rate of heat
development.
 Fineness of cement also affects the rate of heat development but not the total amount
of heat librated.

25. Heat of hydration test
Heat of Hydration determined by ASTM C 186 (left) or
by a conduction calorimeter (right).

26. Heat of hydration test
 The amount of heat generated depends upon the chemical composition of cement. Following are the heat of hydration
generated on hydration of the four compounds of cement.
 Compound Heat of hydration Remarks C3S 502 j/g--C2S 260 j/gMinimumC3A 867 j/g MaximumC4AF 419 j/g--C3S and C3A
are the compounds responsible for the high heat evolution.
 The approximate amount of heat generated using ASTM C 186, during the first 7 days (based on limited data) are as
follows:
Type Name Heat of hydration (kj/kg)
I Normal 349
II Moderate 263
III High early strength 370
IV Low heat of hydration 233
V Sulfate resistant 310