A. Ordinary Portland Cement (OPC)
Ordinary Portland Cement (OPC) is the most widely used cement in the
world for producing concrete, mortar, stucco, and non-specialty grouts. Ordinary
Portland Cement has 3 grades based on its strength namely 33, 43 and 53 grade that
indicates the compressive strength obtained after 28 days of setting.
Indian Standard Codes
Grade
33 Grade
1.Properties
A. Chemical Properties
Ratio of
Not greater than
percentage of lime to
percentages of silica, 1.02 and not less than
0.66
alumina and iron
oxide
Insoluble residue,
Not more than 4
percent by mass
Magnesia, percent
Not more than 6
by mass
Chloride content,
Not more than 0.1
percent by mass,
%
Max
Not more than
alkali content
0.05
B. Physical Properties
3
7
28
Setting Time
days Days Days
Avg. Compressive
Strength in N/mm^2
16
Fineness in m^2 /kg,
Min.
Soundness
a) By Le Chatelier
method, mm, Max
22
43 Grade
Not greater than
Not greater than
1.02 and not less than 1.02 and not less than
0.66
0.8
10
Not more than 2
Not more than 2
Not more than 6
Not more than 6
Not more than 0.1
Not more than 0.1
%
Not more than
0.05
Not more than
0.05
3
days
7
Days
28
Days
3
days
7
Days
28
Days
23
33
43
27
37
53
33
225
53 Grade
22
22
5
5
10
10
Setting time
a) Initial in minutes,
Min
b) Final in minutes,
Max
Code Reference
30
30
30
600
600
600
IS Code – IS 269 :
1989
IS Code – IS 8112:
1989
IS Code – IS 12269 :
1987
B. Rapid Hardening Cement
Rapid Hardening Cement (RHC) are also called high early strength cement. The prime
difference between the rapid hardening cement and ordinary Portland cement is the
lime content. Large proportion of lime is the distinguishing feature of rapid hardening
cement.
Manufacturing Rapid hardening cement is burnt at a higher temperature than that of
the OPC under more controlled conditions.
Strength
The 3 days strength of rapid hardening cement is equivalent to the 7 days strength of
OPC when the water-cement ratio for both the cement is taken to be same. The
increased rate of strength is due to the fact that higher proportion of tri-calcium
silicate (C3S) is contained in RHC along with finer grinding of the cement clinker.
Though, the rate at which RHC gains strength is higher than the rate at which OPC
gains strength, the ultimate strength is only a bit higher for RHC.
Properties
 Initial Setting Time: 30 minutes
 Final Setting Time: 600 minutes
 The specific surface is greater than 3250 cm2/gm.
 RHC is lighter than OPC.
 The curing period for RHC is less.
Uses
Rapid hardening cement is mostly used in construction of road where the traffic
cannot be halted for long period of time. Besides, RHC is used where the formwork
need to be removed early for reuse. It is also used on those circumstances where
sufficient strength for further construction is wanted as quickly as practicable. These
are also used in manufacturing precast slabs, posts, electric poles.
Advantages
 As the curing period for rapid hardening cement is less, it turns out to be
economical.
 Shrinkage during curing and hardening of cement is less in case of RHC.
 RHC are good at Sulphur resistance.
 Good speed of construction can be achieved as the strength is gained in
relatively shorter time.
Disadvantages
 It is expensive than Ordinary Portland Cement.
C. Portland Pozzolana cement
Portland Pozzolana cement is integrated cement which is formed by synthesising OPC
cement with pozzolanic materials in a certain proportion. It is commonly known as PPC
cement. In this article we discuss about the properties, manufacture, characteristics,
advantages and disadvantages of Portland Pozzolana cement.
What is pozzolana or pozzolanic material?
Pozzolana is a volcanic powder found in Italy near Vesuvius. A pozzolanic material
can be a natural or artificial which contains silica and aluminous in a reactive form.
This materials usually doesnt posses any cementitious properties, but when it is mixed
with water or moisture or lime to undergo reaction with calcium hydroxide to
form compounds possessing cement properties.
Manufacture of Portland pozzolana cement

The primary raw materials used for this cement manufacture are limestone
(CaCO2) and clay (SiO2,AI2,O3,Fe2O3). Rocks are loaded into trucks and
transported to the crushers, where the crushed into fine particles.

Fine particles of clay and limestone are fed into the air-swept ball mills in
desired proportions as per requirement and mixed very well before it is sent to
silos for storing.

This mixture is then pre-heated upto 800-1000c where calcinations of CACO3
to CaO takes place.
The pre heated mixture is then sent into kiln where the mixture is heated to
1450C in rotary Kiln. The modules formed from the burning process called
clinker. The clinker is cooled by a rotary cooler.
This clinker is now mixed with gypsum and pozzolana materials in the required
proportion and thus the Portland Pozzolana Cement is obtained.


Properties of Portland Pozzolana Cement

Initial setting time = 30 min (minimum)

Final setting time = 600 min (maximum).
At 3 days 13MPa (minimum)
At 7 days 22 MPa (minimum)
At 28 days 33 MPa (minimum)
Drying shrinkage should not be more than 0.15%
Fineness should not be less than 300 m2/kg







Initial strength of PPC is less but final strength is equal to the 28 days strength
of OPC
PPC has lower rate of development of strength than OPC
Uses of Portland Pozzolana Cement
1. Used in hydraulic structures, marine structures, construction near the sea shore,
dam construction etc.
2. Used in pre-stressed and post-tensioned concrete members.
3. Used in masonry mortars and plastering.
4. As it gives better surface finish, it is used in decorative and art structures.
5. Used in manufacture of precast sewage pipes.
6. Used under harsh concreting conditions.
Advantages of Portland Pozzolana Cement
1. It is an eco-friendly cement as the material used in the manufacture are made of
natural recycled waste.
2. It is very fine cement hence very good when used for plastering works.
3. Pozzolano consists of silica material which makes it cheap and hence reduces
the cost of the cement making it economical to use.
4. Pozzolana cement has very good resistance against sulphate attack hence is
used in hydraulic structures, marine structures, construction near the sea shore,
dam construction etc.
5. PPC used in pre-stressed and post-tensioned concrete members.
6. Pozzolano consists of silica material which makes it cheap and hence reduces
the cost of the cement making it economical to use.
7. Pozzolana cement has very good resistance against sulphate attack hence is
used in hydraulic structures, marine structures, construction near the sea shore,
dam construction etc.
8. PPC used in pre-stressed and post-tensioned concrete members.
Disadvantages of Portland Pozzolana Cement
1. The initial strength obtained is less, which effect the de-shuttering of supports
early.
2. As it contains more fine material, handing of concrete is difficult.
3. When compared to the OPC setting time is less for PPC
4. Reduction in alkanity reduces the resistance to corrosion of steel reinforcement
5. As the strength of this concrete gains slowly, curing process is very important.
Any error in this could cause durability problems.
D. Quick Setting Cement
It is one of the type of cements where the initially set in 5 mins and final set is achieved
in 30 mins, which is used in the special conditions of construction like in running water.
In this article we study about the properties, phenomenon, uses, advantages and
disadvantages of quick setting cement.
Phenomenon of Quick setting cement
Generally, when the water is added into the cement hydration takes places and the
chemical reaction occurs which make the cement to harden where the initial setting time
is 30 mins and final setting time being 10hrs. In this special type of cement, where the
setting time of the cement is to be less and hardening of cement to be fast. The cement
clinkers are grinded with aluminium sulphate, which accelerates the setting time of
cement. aluminium sulphate is used as accelerating admixture in the dosage range of
1% to 3% by weight of cement clinkers .The mechanism of function of aluminium
sulphate is that it increases the rate of hydration of tricalcium silicate (C3S) and
tricalcium aluminate (C3A) phases of cement, thereby providing earlier heat evolution
and strength development. It acts as a catalyst in the hydration of tricalcium silicate
(C3S) and tricalcium aluminate (C3A). Concrete specimens with varying percentage of
aluminium sulphate were tested for compressive strength, splitting tensile strength and
flexural strength. The results obtained were compared with results of normal M-20
concrete mix and it was found that maximum increase in compressive strength, splitting
tensile strength and flexural strength occurred for quick setting cement concrete at 3
days age and 7 days age. However, there was no considerable increase in compressive
strength, splitting tensile strength and flexural strength at 28 days age.
Uses of Quick setting cement
1.
2.
3.
4.
It is used in under water construction.
It is also used in rainy & cold weather conditions.
Where, quick strength is needed in short span of time.
Used higher temperature where water evaporates easily.
5. Used for anchoring or rock bolt mining and tunnelling
6. Used for fixing concrete steps.
7. For the anchorage of Rock Bolt in Tunnel & all works underground, quick
setting cement is required.
Disadvantages of Quick setting cement
1. Due to content of sulphates in the aluminium sulphate, there are major chance
of sulphate attack on the reinforcement corrosion and durability is
compromised.
2. When water is added the work should be completed fast or else it sets and
difficult to mix.
3. In quick setting cement, if the heat is not dissipated properly it can result in
cracks in the cement after setting.
4. It is not widely available.
5. It is expensive.
E. Sulphate Resisting Cement
Sulphate Resisting Cement is a type of Portland cement in which the amount of
tricalcium aluminate (C3A) is restricted to lower than 5% and (2C 3A +C4AF) lower
than 25%, which reduces the formation of sulphate salts. The reduction of sulphate salts
lowers the possibility of sulphate attack on the concrete. In this article we study about
the composition, properties, characteristics, uses, advantages and disadvantages of
sulphate resisting cement.
Composition of Sulphate Resisting Cement
Due to very low range of tricalcium aluminate in sulphate resisting cement, a very
small quantity of calcium aluminate is formed on hydration. The formation of calcium
sulpho- aluminates which formed due to reaction of calcium sulpho-aluminates which
formed due to reaction of calcium sulphoaluminate and sulphate salts is considerably
reduced with use of sulphate resisting cement. The sulphate aluminates are highly
expansive in nature and cause maximum damage to the concrete.
Properties of Sulphate Resisting Cement
Property
Values
Fineness
280+ or -10 sq m /kg
Setting time
Initial
80 min
Final
240 min
Soundness
Lechatelier (mm)
2 (max)
Compressive strength
3 days
30 + or - 3
7 days
45 + or - 3
28 days
65 + or - 3
Tri calcium aluminate
0.035
Magnesia
0.02
Loss on ignition
0.02
Characteristics of Sulphate Resisting Cement
1. This cement provides maximum resistance to chloride ions - minimising the
risk of corrosion of reinforced steel.
2. It also provides high level of concrete performance and structural integrity in
highly aggressive sulphate and acidic environments.
3. It also has increased workability and pumpability.
4. This cement has significantly improved later-age concrete strengths.
Uses of Sulphate Resisting Cement
Sulphate Resisting Cement is recommended for following type of constructions:
1. Foundations.
2. Piling works.
3. Construction in contact with soils or ground water having more than 0.2% or
0.3 % g/l sulphate salts respectively.
4. Concrete surfaces subjected to alternate wetting and drying such as bridge
piers, concrete surface in tidal zone, apron etc.
5. Effluent treatment plans.
6. Chimney, cooling towers.
7. Coastal protective works such as sea walls, break waters, tetrapods etc.
8. Building near seacoast.
9. Chemical industries, water storage, sumps, drainage works.
10. Suitable for underground works where Sulphate is present in the Soil and
water.
Advantages of Sulphate Resisting Cement
1. The use of sulphate resisting cement provides excellent protection against the
formation of sulpho-aluminates and consequent resistance to concrete against
sulphate attack.
2. Very high compressive strength by economic concrete mix design.
3. Very low heat of hydration helps to avoid shrinkage cracks.
4. Improves life and durability of structures under aggressive conditions.
5. Improves corrosion resistance of steel by preventing sulphate attack.
Disadvantages of Sulphate Resisting Cement
1. Sulphate resisting cement is not suitable where there is danger of chloride
attack. This will cause corrosion of rebar.
2. If both Chlorides and Sulphates are present, Ordinary Portland Cement with
C3A between 5 & 8 should be used.
3. Curing process should be done properly with great care for min of 8-10 days.
4. It is not prescribed to use it in marine construction.
F. Blast furnace slag cement
Blast furnace slag cement is the mixture of ordinary Portland cement and fine granulated
blast furnace slag obtained as a by-product in the manufacture of steel with percent
under 70% to that of cement. Ground granulated blast furnace slag cement (GGBFS) is
a fine glassy granules which contain cementatious properties. In this article we discuss
about the manufacture, constituents, properties, uses, advantages and disadvantages
of Blast-furnace slag cement. Blast furnace slag cement is the mixture of ordinary
Portland cement and fine granulated blast furnace slag obtained as a by product in the
manufacture of steel with percent under 70% to that of cement. Ground granulated blast
furnace slag cement (GGBFS) is a fine glassy granules which contain cementatious
properties. In this article we discuss about the manufacture, constituents, properties,
uses, advantages and disadvantages of Blast-furnace slag cement.
Manufacture and Constituents of Blast-Furnace Slag
Cement
GGBFS is obtained as a by-product in the extraction of iron from it ore. The process
of extraction of iron is blast furnace. The slag that is obtained on the iron ore is
separated and cooled down slowly, which results in the formation of nonreactive
crystalline material.
Constituents of the Ground Granulated Blast Furnace Slag
Constituents
% by mass
SiO2
27-39%
Al2O3
8- 20%
CaO
38-50%
MgO
<10%
Further this slag is grounded finely as that of cement and mixed in the proportion as
per the requirement. Different percentage of GGBFS is added for different type of
construction.
Proportion of slag percentage for different applications.
Application in Type of Construction
Slag Proportion in %
General construction
20-40
Reduction of heat hydration
50-80
Structures exposed to chloride attack
50-81
Structures exposed to sulfate attack
50-82
Marine structures
60-80
Properties of Blast-Furnace Slag Cement
Properties
Values
Density (g/cm3)
3.04
Specific Surface Area (cm2/g)
4050
Setting Time
Initial Setting
60min
Final Setting
600min
Compressive Strength (N/mm2)
3days
23.5
7days
36.1
28days
62.4
Chemical Composition (%)
Magnesium oxide
2.88
Sulphur tri oxide
2.19
Ignition loss
1.47
Uses of Blast-Furnace Slag Cement
1. Used in ready mix concrete plants.
2. Used for structures meant for water retaining such as retaining wall, rivers,
ports, tunnels for improvement in impermeability.
3. Used in mass concreting works such as dams, foundations which require low
heat of hydration.
4. Used in the places susceptible to chloride and sulphate attacks such as substructure, bored piles, pre-case piles and marine structures.
Advantages of Blast-Furnace Slag Cement
1. The initial strength achieved is lesser than that of conventional concrete, but
the higher ultimate strength gained is equal and sometimes higher that
conventional concrete.
2. As the slag is grounded finely, it has the capacity to fill the pores efficiently,
workability is high and bleeding is low.
3. It has good resistance towards sulphate and chloride attack and even less risk
of alkali-silica reaction with aggregates.
4. Due to slow hydration process, the slump retention and initial setting time is
more.
5. Greater durability and reduced permeability due to fineness.
6. The hydration process if slag is an exothermic process, thus the generation of
heat of hydration is slow. Due to this property, this type of cement can be used
where the problem of thermal cracking is foreseen.
7. As the colour of GGBFS is white, the cement colour obtained is lighter
coloured when compared to conventional cement.
8. The production cost this cement is less when compared to OPC.
Disadvantages of Blast-Furnace Slag Cement
1. Initial Strength is low, due to this it cannot be used in RCC works.
2. As the initial setting time is high, this cement is not used for emergency or
repair works
G. High Alumina Cement
High Alumina Cement is manufactured by grinding the clinkers of alumina and
calcareous material such as lime by fusing or sintering process. This cement is also
known as calcium aluminum cement. In this article we discuss about the history,
composition, manufacture, characteristics, uses, advantages and disadvantages.
History of High Alumina Cement
High Alumina Cement was first developed in United Kingdom in 1925 by a cement producer by
name Lafarge. As it was found to be resistant to chemical attacks it was primarily used for marine
construction. Its popularity rose when the properties of this cement such as rapid strength gain
and easy to manufacture were found out and widely used for precast concreting.
Fig 1: High Alumina Cement.
Composition of High Alumina Cement
Table 1 : Composition percentage of constituents.
Constituents
Content Percentage
Silica
3-8%
Alumina
37-41%
Lime
36-40%
Iron Oxide
9-10%
Titanium
1.5-2%
Magnesium
1%
Insoluble Resides
1%
Manufacture of High Alumina Cement
The process of manufacture of High Alumina Cement is different compared to that of
ordinary portland cement. Bauxite and lime are used as the raw material. The raw
materials are mixed in the required proportion and grinded into small fragments of
100 mm. These lumps are fed in kiln and heated up-to their fusion point which is
1600°C. The molten material fall down on the steel plate and it is send to cool down
in rotary kiln. These clinkers are then grounded finely in tube mills unto the fineness
not less than 2250 cm2/gram is achieved.
Characteristics of High Alumina Cement
The characteristics of this cement are,
 It is very resistant to chemical attacks.
 The pH level is low.
 High resistant to chemical corrosion, due to which it is used
for construction of water pipes, sewage pipes, factory drains, coastal
constructions and in factory chimneys.
 The refractive index of this cement is high.
 It has high durability in sulphuric acid.
 Hardening property of this cement is fast.
 It acts as a bonding material when added in refractory castables because it
forms ceramic bond at high temperatures.
Uses of High Alumina Cement
1. Due the property of rapid hardening and strength, it is widely used in marine
construction and sewer infrastructure.
2. High alumina cement is also used in refractory concretes where it requires
more strength at very high temperature.
Advantages of High Alumina Cement
The advantages of High Alumina Cement are as follows,
1. Due to the more setting time, time for mixing and placing is more.
2. The resistance for the chemical action is good.
3. Can withstand high temperature.
4. Frost action is low as the heat evolved is more during setting.
5. High alumina cement is very reactive and has very high compressive strength.
6. High resistant to fire.
Disadvantages of High Alumina Cement
The disadvantages of high alumina cement are as follows,
1. As the heat required for the manufacture of this cement is more, the
manufacturing cost of this cement is high.
2. As the fineness is kept not less than 2250 cm2/gram, which is very fine. Care to
be taken that it doesn't come in contact with human eye or mouth.
3. As the heat evolution while setting is high, it cannot be used in mass concreting
works