An industry for producing a material of ever increasing
• Introduction to cement industry
• Raw materials
• Location of cement industry(In Pakistan)
• Manufacturing of cement
• Setting of cement
• Applications of cement
• Advantages and Disadvantages of cement
GROUP MEMBERS NAME
HAFIZ MUHAMMAD UBAID ARIF
ALI HAIDER RIZI
MUHAMMAD TAHIR MEHMOOD
A material obtained by burning a mixture of
calcarious and argillaceous material at sufficiently high
temperature to produce clinkers.
These clinkers are then ground to a fine powder
Important building material
Applied everywhere in the construction of houses ,public
buildings ,roads, industrial plant ,dams ,bridges and many
A building material which was firstly introduce by English
scientist Mason joseph Aspdin.
He found it when strongly heated mixture of limestone and
clay was mixed with water and allowed to stand.
It hardened to stone like mass which resembled Portland
rock(a famous building stone of England.
The name of Portland cement is given to mixture of
lime(obtained from limestone), silica, iron, alumina.
Important raw material used for the manufacturing of cement are:
(i) calcarious material
(ii) argillaceous material
D. Marine shell
These are the source of calcium oxide
Iron oxide 2.5%
Sulphur trioxide 1.5%
Location of cement industries
Currently many cement industries are located in Pakistan in
different areas, however some of the obvious ones are:
• Bestway LTD (two in KPK and one in Punjab)
• Nishat Group (Two in Punjab and one in Baluchistan)
• Fauji Foundation( Two in Islamabad and one in Peshawar)
• Askari cement limited(Nizampur and wah)
• Pioneer Cement limited(Punjab)
Manufacturing of cement
• Manufacturing of cerement by two ways
a) Dry process
b) wet process
• Most industries use wet process for cement manufacturing
involving following steps:
1. Crushing and grinding of raw material
2. Mixing of material in correct proportion
3. Grinding the heated product known as clinker
4. Mixing and grinding of cement clinker with gypsum
1. Crushing and grinding
In the presence of water in rotating
cylindrical balls and tube mills
2. Mixing of Raw material
Limestone 75%, Clay25%
Homogenized by using air compressed
Water content is reduced from 45% to
3. Heating the slurry in rotary kiln
Three different zones
A. Pre-heating zone : The clay is broken down into Al2O3, SiO2 and
B. Decomposition zone : lime stone decomposes into lime and CO2
CaCO3 CaO + CO2
C. Burning zone : Oxide combine with silica to form silicates
CaO + SiO2 CaSiO3
D. Cooling zone : The charge of silicates is cooled up. Greyish black
clinkers are obtained
4. Grinding the clinkers with gypsum
• Cement Clinkers are air-cooled.
• 2% gypsum is first ground and then mixed with
5. Storage and bagging
Finished cement is pumped to storage silos where it
is packed into paper bags and dispatched for bulk
The conversion of a paste of cement to a rigid mass is known
as Setting of cement.
Cement is mixed with water
C3A + 6H2O C3A . 6H2O E= -880
Hyderated Tricalcium Aluminate
To avoid early setting of C3A , Gypsum is added which
acts as retarding agent.
C3A + 3CaSO4 . 2H2O C3A . 3CaSO4 . 2H2O
Caclium Sulpho Aluminate
After hydration, Hydrolysis of C3A, C3S starts to give tobermonite
gel and crystalline Ca(OH)2, which is responsible for initial
strength of the cement.
The Hydrolysis of C3S gets completed within 7 days
2C3S + 6H2O C3S2 . 3H2O + 3Ca(OH)2
• Initial Setting
The initial time refers to the
time that cement turns into
paste by mixing with water
and begins to lose its
• Final Setting
The time that cement completely
loses its plasticity by mixing with
water and begins to have a certain
structural strength is known as
the final setting time.
Composition of cement.
Amount of gypsum in cement
Fineness of cement
Water Cement Ratio
Type of admixture used
Storage of cement
1.To prepare cement mortar
2.To prepare cement concrete
3.To build fire proof and thermal proof structures
4.To build hydrographic and frost resistant structures
5.To construct Cement concrete roads
6.For aesthetic concrete construction
Application of Cement
Mortar is a workable paste which hardens to bind building
blocks such as stones, bricks, and concrete masonry
units, to fill and seal the irregular gaps between them,
spread the weight of them evenly, and sometimes to add
decorative colors or patterns to masonry walls
Cement As Mortar
In its simplest form, concrete is a mixture of paste and
aggregates. Cement is actually an ingredient of concrete.
It is the fine powder that, when mixed with water, sand, and
gravel or crushed stone (fine and coarse aggregate), forms the
rock-like mass known as concrete.
Cement As Concrete
To with stand against high temperatures and
to prevent fire accidents structures should be
built with great fire-resistant materials like
cement. High alumina cement is more suitable
material to make concrete for the structures in
high temperature regions.
To Build Fire Proof or Heat Proof Structures
Most of the hydrographic structures in the world are built using
concrete with cement as binding material. The structures built in
water or in contact with water should be very strong against
moisture and they should be water tight.
To Build Hydrographic and Frost Resistant Structures
Cement concrete roads are more famous as high standard roads which are
stronger than all other types of roads. They are also called as rigid pavements
because of their rigid nature. C.C roads have long life span even without proper
maintenance. Load wise also they are much capable than all other types.
To Construct Cement Concrete Roads
Now a days cement is available in many colors. This is done by adding coloring
agent while manufacturing cement but the percentage of coloring agent should be
below 10%. Some of the coloring agents are iron oxide which gives red or brown,
cobalt which gives blue etc.
The colored cement makes the structure beautiful without any painting. Colored
cements generally used for floor finishing, stair treads, window sill slabs, external
wall surfaces etc..
For Aesthetic Structures
Disadvantages of Cement
M Tahir Mehmood
1.The cement has good plasticity before coagulation and can be poured into
various shapes and sizes of components or structures.
• Cement has a slow rate of heat transfer, which means that concrete walls in
a home act as a fire shield.
• Durability of cement is ability to resist weathering action and chemical attack.
Types of durability:
• Physical Durability is against freezing and thawing action, permeability of water,
• Chemical Durability is against alkali aggregate reaction, sulphate attack, chloride ingress etc.
Advantages Of Cement (Cont.)
4.Cement is resistant to wind and water. Therefore, it is very useful in storm shelters.
5.cement is free from defects and flaws.
6.It has high thermal mass(moderates' temperature)
7.Materials used in the production of concrete are easily available.
8.It can be sprayed and can be used to rectify small cracks.
9.It can be pumped and placed even in very difficult locations.
10.It provides quickness and ease in the construction of monolithic members of the
Shrinkage is a main cause of cracking. As concrete hardens and dries it shrinks. This
is due to the evaporation of excess mixing water. This shrinkage causes forces in the
concrete which literally pull the slab apart. Cracks are the result of these forces.
To avoid the development of cracks, steel is used as reinforcement.
2.Cement is less ductile.
3.Compared to other binding materials, the tensile strength
of cement is relatively low.
Disadvantages Of Cement (Cont.)
4.It contains soluble salts. Soluble salts cause efflorescence.
5.Cement is not fully impermeable material.
6.It is not ideal for situation when settlement is expected.
7.Due to the more weight of concrete, more reinforcement is needed, which increases
the cost of the structure.
8.It is very sensitive with water content in the mixture.
9.Long curing time(Cure time is the time that determines how long things take to
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