BUILDING
MATERIAL
, CHAPTER – CEMENT
❖ CEMENT
• Concrete is a mixture cement, sand water, aggregates and admixtures.
• Cement is a binder that sets, hardens and adheres (chipkna) to other materials to bind
them together.
• Cement used in construction are usually inorganic, often lime or calcium silicate based
product.
❖ ON THE BASIS OF MANUFACTURING, CEMENT IS CLASSIFIED IN 2
CATEGORIES:
1. Natural cement (roman cement)
• Some special type of rock having 20 – 40 % clay (alumina), CaCO3 (lime stone),
magnesia etc. have the property to make a natural cement.
• Not produced and used in india.
• Strength of natural cement <<< strength of artificial cement.
2. Artificial cement
• In India, artificial cement was firstly manufactured in 1913.
• It is generally made from 2 types of components:
✓ Calcareous (CaCO3 content is predominantly present)
✓ Argillaceous (clay/alumina content is predominantly present)
➢ Ordinary Portland Cement (hydraulic cement)
• Invented by joseph aspdin (1824)
• Before cement, lime was used as binding material.
• Cement have Adhesive and Cohesive property.
• Density = 1440 Kg/m3
• Specific gravity = 3.14 – 3.15
• Mass of 1 bag of cement = 50 Kg
• Volume of 1 bag = 0.0348 m3
, • Modern inventor of cement was Mr. P. Johnson who first introduced the rotary kiln for
manufacturing of cement (1886).
❖ GRADE OF ARTIFICIAL CEMENT
1. 33 – Grade
• IS : 269 : 1989
• Compressive strength after 28 days curing is 33 N/mm2
• Use: general construction (small RCC work)
2. 43 – grade (most imp. Grade)
• IS : 8112 : 1989
• Compressive strength after 28 days curing is 43 N/mm2
• Use: all RCC work
3. 53 – grade
• IS : 12269 : 1987
• Compressive strength after 28 days curing is 53 N/mm2
• Use: high rise buildings, mass concreting.
Note: nowdays all these grades are studies using IS 269 : 1989
➢ IS : 10262 has classified the OPC grade wise from A to F based on 28 days
compressive strength as follows:
• 33, 43 and 53 grade of cement corresponds to categories A,
C and E, respectively
•Most of the 43 grade cement available in market fall in
category D and 53 grade cement in category F
,❖ INGREDIENTS OF CEMENT
1. Lime (CaO) (62 – 65 %)
• It imparts strength and soundness (resistance against the expansion).
• In excess, cement becomes unsound.
• In deficiency, strength will reduce.
2. Silica (SiO2) (17 – 25 %)
• It also imparts strength of cement.
• In excess, strength of cement increases with prolong of setting time.
• In deficiency, strength will decrease.
• Silica is responsible for production of C2S & C3S which are the main component of
cement.
3. Alumina (Al2O3) (3 -8 %)
• It imparts quick setting of cement.
• It reduces the temp. of clinker (3- 20 mm hard round balls formed at high temp.)
• In excess, cement becomes weak
4. Iron oxide (Fe2O3) (0.5 – 6 %)
• It imparts strength, colour & hardness.
• It gives reddish brown colour to cement
• In excess, difficulty creates in binding more fuel consumption.
, • In deficiency, hardness of clinker decreases.
5. Magnesia (MgO) (1 – 4 %)
• It imparts the soundness of cement.
• It gives yellow tint to cement.
• In excess, cement becomes unsound.
• It helps in chemical reaction in cement.
• MgO
6. Sulphur (S) (1 – 3 %)
• It imparts soundness of cement.
• It is present in the form of SO2 & SO3 in cement.
• In excess, cement become unsound.
7. Alkalies (K2O, Na2O) (0.1 – 1 %)
• These are the undesirable properties of the cement and not an ingredient.
• These give the efflorescence to the cement in the atmosphere.
Efflorescence: alkali absorb moisture content or water and form white grey spot on the
surface of cement
• Alkalies also increases the setting time of cement.
NOTE:
• Lime + silica = 70 – 80 %
• Soundness is given by 3 components of cement – LSM (lime, sulphur, magnesia)
• Le chatlier apparatus is used to test soundness due to lime.
• No test is available for test of soundness due to sulphur.
• Gypsum (CaSO4 .2H2O) is used as a retarder in cement.
• Calcium sulphate is present in the form of gypsum in cement.
• Gypsum is used in 3 – 4 % in cement and increases initial setting time of cement
,❖ MANUFACTURING OF CEMENT
DRY PROCESS
WET PROCESSS
• Better quality cement is produced using wet process.
,1. Jaw crusher
• It is used for crushing of large particle into small particle.
2. Ball mill
• It is used for coarse grinding of raw material.
3. Wash mill
• It is used for making slurry by wet grinding of the material.
• L = 8 – 10 m, Dia. =2.5 to 4 m, having cylindrical shap.
• It rotates at 15 to 20 rpm.
4. Tube mill
• It is used for fine grinding.
• L = 6 – 9 m, Dia 2 – 2.5 m
• It has cylindrical shape which can fine grind the 25 mm particle.
5. Rotary kiln
• Main instrument used in manufacturing of cement
• It has 4 zones
✓ Zone 1 – drying zone
✓ Zone 2 – calcination (heating something till redness) zone
✓ Zone 3 – clinker zone
✓ Zone 4 – rotary cooler (decicator)
• Roatry kiln can rotate at 1 – 3 rpm.
• Inside surface of rotary kiln is made of
refractory bricks (fire bricks).
• Zone 1 (Temp. 250 – 500 0 C)
Moisture present in slurry or powdered
raw material is removed and gas
liberated.
• Zone 2 (Temp. 700 – 1200 0 C)
In this zone slurry/ powdered raw material is obtained in the semi-solid state & form the
nodules & due to gravity forwarded to next zone.
,• Zone 3 (Temp. 1400 – 1500 0 C)
✓ It is the highest temp. zone.
✓ In this zone some chemical components are made which are at high temp. and in
melt form.
✓ Due to surface tension, these melt particles change into 3 – 20 mm round balls
which are called clinker.
• Zone 4 (desiccators)
✓ It is used to cool down the clinker for upcoming grinding process.
✓ At the exit door clinker temp. should be about 100 – 200 0 C before grinding
❖ BOUGE’S COMPOUND
• When water is mixed in cement, it reacts with component of cement and produce
chemical compounds which are called bouge’s compound.
• These are discovered by Mr. Bouge’s that’s why these are called bouge’s compound.
• Le Chatelier and Borhoman also observed about clinker and find similar compounds as
bouge and thus are following:
✓ Alite – C3S (main component of cement)
✓ Belite – C2S (second main component)
✓ Celite – C3A (responsible for setting of cement)
✓ Felite – C4AF
• Imp. Note:
✓ Hydration process: all the chemical reaction after mixing water in cement is called
hydration process.
✓ Heat of hydration: heat liberated at mixing water in cement.
✓ To control the reaction of water with cement clinker 3 – 4 % gypsum is mixed.
,1. C3A (tricalcium Aluminate)
• This is the first chemical compound that is formed after mixing water in cement
• Formed within 24 hours of mixing water.
• 12 – 14 %
• Responsible for initial and final setting time.
• Responsible for all undesirable properties.
• Mainly responsible for flash setting.
• To increase the setting time of cement, C3A is counter attacked by gypsum.
• If the % of C3A is less, then sulphate resisting property is high.
• To make the sulphate resistance cement C3A 5%
• Heat of hydration is max. for C3A (865 joule/gram)
2. C4AF (Tetra calcium aluminoferrate)
• 6 – 10 %
• Formed within 24 hours of mixing water.
• Minorly responsible for flash setting.
• Heat of hydration = 420 joule/gram
• Also responsible for fusion of particle.
3. C3S (Tri calcium silicate)
• 45 – 65 %
• It forms within a weak.
• Responsible for initial strength of cement (7 days strength).
• Heat of hydration = 500 joule/gram
• If the % of C3S is increased then the heat of hydration also increases.
4. C2S (Di calcium silicate)
• 15 – 35 %
• It is formed in 1 year.
, • It is responsible for ultimate strength/ final strength of cement.
• It gives resistance power against freezing and thawing.
• It is the 2nd main component.
• It gives min. heat of hydration (260 joule/gram)
IMP. NOTE:
• If we want to increase initial strength of cement – inc. C3S
• If we want to increase ultimate strength of cement – inc. C2S
• Order according to weightage – C3S > C2S > C3A > C4AF
• Order according to chemical reaction – C3A > C4AF > C3S > C2S
• Order according to heat of hydration
Final – C3A > C3S > C4AF > C2S
3 days – C3A > C4AF > C3S > C2S
90 days – C3A > C3S > C4AF > C2S
• Order according to rate of hydration – C4AF > C3A > C3S > C2S
• Heat of hydration is measured using calorimeter.
➢ Requirement of water
• 23 % water by weight of cement is required to start the process of heat of hydration
and 38 % water by weight of cement is required to finish the process completely.
• 23 % water is for hydration of (C3S, C2S) and 15 % water is required for filling the
void.
• Generally, cement absorbs 2 % of hygroscopic water, but if it absorbs 5% of
hygroscopic water then the cement becomes useless.
MATERIAL
, CHAPTER – CEMENT
❖ CEMENT
• Concrete is a mixture cement, sand water, aggregates and admixtures.
• Cement is a binder that sets, hardens and adheres (chipkna) to other materials to bind
them together.
• Cement used in construction are usually inorganic, often lime or calcium silicate based
product.
❖ ON THE BASIS OF MANUFACTURING, CEMENT IS CLASSIFIED IN 2
CATEGORIES:
1. Natural cement (roman cement)
• Some special type of rock having 20 – 40 % clay (alumina), CaCO3 (lime stone),
magnesia etc. have the property to make a natural cement.
• Not produced and used in india.
• Strength of natural cement <<< strength of artificial cement.
2. Artificial cement
• In India, artificial cement was firstly manufactured in 1913.
• It is generally made from 2 types of components:
✓ Calcareous (CaCO3 content is predominantly present)
✓ Argillaceous (clay/alumina content is predominantly present)
➢ Ordinary Portland Cement (hydraulic cement)
• Invented by joseph aspdin (1824)
• Before cement, lime was used as binding material.
• Cement have Adhesive and Cohesive property.
• Density = 1440 Kg/m3
• Specific gravity = 3.14 – 3.15
• Mass of 1 bag of cement = 50 Kg
• Volume of 1 bag = 0.0348 m3
, • Modern inventor of cement was Mr. P. Johnson who first introduced the rotary kiln for
manufacturing of cement (1886).
❖ GRADE OF ARTIFICIAL CEMENT
1. 33 – Grade
• IS : 269 : 1989
• Compressive strength after 28 days curing is 33 N/mm2
• Use: general construction (small RCC work)
2. 43 – grade (most imp. Grade)
• IS : 8112 : 1989
• Compressive strength after 28 days curing is 43 N/mm2
• Use: all RCC work
3. 53 – grade
• IS : 12269 : 1987
• Compressive strength after 28 days curing is 53 N/mm2
• Use: high rise buildings, mass concreting.
Note: nowdays all these grades are studies using IS 269 : 1989
➢ IS : 10262 has classified the OPC grade wise from A to F based on 28 days
compressive strength as follows:
• 33, 43 and 53 grade of cement corresponds to categories A,
C and E, respectively
•Most of the 43 grade cement available in market fall in
category D and 53 grade cement in category F
,❖ INGREDIENTS OF CEMENT
1. Lime (CaO) (62 – 65 %)
• It imparts strength and soundness (resistance against the expansion).
• In excess, cement becomes unsound.
• In deficiency, strength will reduce.
2. Silica (SiO2) (17 – 25 %)
• It also imparts strength of cement.
• In excess, strength of cement increases with prolong of setting time.
• In deficiency, strength will decrease.
• Silica is responsible for production of C2S & C3S which are the main component of
cement.
3. Alumina (Al2O3) (3 -8 %)
• It imparts quick setting of cement.
• It reduces the temp. of clinker (3- 20 mm hard round balls formed at high temp.)
• In excess, cement becomes weak
4. Iron oxide (Fe2O3) (0.5 – 6 %)
• It imparts strength, colour & hardness.
• It gives reddish brown colour to cement
• In excess, difficulty creates in binding more fuel consumption.
, • In deficiency, hardness of clinker decreases.
5. Magnesia (MgO) (1 – 4 %)
• It imparts the soundness of cement.
• It gives yellow tint to cement.
• In excess, cement becomes unsound.
• It helps in chemical reaction in cement.
• MgO
6. Sulphur (S) (1 – 3 %)
• It imparts soundness of cement.
• It is present in the form of SO2 & SO3 in cement.
• In excess, cement become unsound.
7. Alkalies (K2O, Na2O) (0.1 – 1 %)
• These are the undesirable properties of the cement and not an ingredient.
• These give the efflorescence to the cement in the atmosphere.
Efflorescence: alkali absorb moisture content or water and form white grey spot on the
surface of cement
• Alkalies also increases the setting time of cement.
NOTE:
• Lime + silica = 70 – 80 %
• Soundness is given by 3 components of cement – LSM (lime, sulphur, magnesia)
• Le chatlier apparatus is used to test soundness due to lime.
• No test is available for test of soundness due to sulphur.
• Gypsum (CaSO4 .2H2O) is used as a retarder in cement.
• Calcium sulphate is present in the form of gypsum in cement.
• Gypsum is used in 3 – 4 % in cement and increases initial setting time of cement
,❖ MANUFACTURING OF CEMENT
DRY PROCESS
WET PROCESSS
• Better quality cement is produced using wet process.
,1. Jaw crusher
• It is used for crushing of large particle into small particle.
2. Ball mill
• It is used for coarse grinding of raw material.
3. Wash mill
• It is used for making slurry by wet grinding of the material.
• L = 8 – 10 m, Dia. =2.5 to 4 m, having cylindrical shap.
• It rotates at 15 to 20 rpm.
4. Tube mill
• It is used for fine grinding.
• L = 6 – 9 m, Dia 2 – 2.5 m
• It has cylindrical shape which can fine grind the 25 mm particle.
5. Rotary kiln
• Main instrument used in manufacturing of cement
• It has 4 zones
✓ Zone 1 – drying zone
✓ Zone 2 – calcination (heating something till redness) zone
✓ Zone 3 – clinker zone
✓ Zone 4 – rotary cooler (decicator)
• Roatry kiln can rotate at 1 – 3 rpm.
• Inside surface of rotary kiln is made of
refractory bricks (fire bricks).
• Zone 1 (Temp. 250 – 500 0 C)
Moisture present in slurry or powdered
raw material is removed and gas
liberated.
• Zone 2 (Temp. 700 – 1200 0 C)
In this zone slurry/ powdered raw material is obtained in the semi-solid state & form the
nodules & due to gravity forwarded to next zone.
,• Zone 3 (Temp. 1400 – 1500 0 C)
✓ It is the highest temp. zone.
✓ In this zone some chemical components are made which are at high temp. and in
melt form.
✓ Due to surface tension, these melt particles change into 3 – 20 mm round balls
which are called clinker.
• Zone 4 (desiccators)
✓ It is used to cool down the clinker for upcoming grinding process.
✓ At the exit door clinker temp. should be about 100 – 200 0 C before grinding
❖ BOUGE’S COMPOUND
• When water is mixed in cement, it reacts with component of cement and produce
chemical compounds which are called bouge’s compound.
• These are discovered by Mr. Bouge’s that’s why these are called bouge’s compound.
• Le Chatelier and Borhoman also observed about clinker and find similar compounds as
bouge and thus are following:
✓ Alite – C3S (main component of cement)
✓ Belite – C2S (second main component)
✓ Celite – C3A (responsible for setting of cement)
✓ Felite – C4AF
• Imp. Note:
✓ Hydration process: all the chemical reaction after mixing water in cement is called
hydration process.
✓ Heat of hydration: heat liberated at mixing water in cement.
✓ To control the reaction of water with cement clinker 3 – 4 % gypsum is mixed.
,1. C3A (tricalcium Aluminate)
• This is the first chemical compound that is formed after mixing water in cement
• Formed within 24 hours of mixing water.
• 12 – 14 %
• Responsible for initial and final setting time.
• Responsible for all undesirable properties.
• Mainly responsible for flash setting.
• To increase the setting time of cement, C3A is counter attacked by gypsum.
• If the % of C3A is less, then sulphate resisting property is high.
• To make the sulphate resistance cement C3A 5%
• Heat of hydration is max. for C3A (865 joule/gram)
2. C4AF (Tetra calcium aluminoferrate)
• 6 – 10 %
• Formed within 24 hours of mixing water.
• Minorly responsible for flash setting.
• Heat of hydration = 420 joule/gram
• Also responsible for fusion of particle.
3. C3S (Tri calcium silicate)
• 45 – 65 %
• It forms within a weak.
• Responsible for initial strength of cement (7 days strength).
• Heat of hydration = 500 joule/gram
• If the % of C3S is increased then the heat of hydration also increases.
4. C2S (Di calcium silicate)
• 15 – 35 %
• It is formed in 1 year.
, • It is responsible for ultimate strength/ final strength of cement.
• It gives resistance power against freezing and thawing.
• It is the 2nd main component.
• It gives min. heat of hydration (260 joule/gram)
IMP. NOTE:
• If we want to increase initial strength of cement – inc. C3S
• If we want to increase ultimate strength of cement – inc. C2S
• Order according to weightage – C3S > C2S > C3A > C4AF
• Order according to chemical reaction – C3A > C4AF > C3S > C2S
• Order according to heat of hydration
Final – C3A > C3S > C4AF > C2S
3 days – C3A > C4AF > C3S > C2S
90 days – C3A > C3S > C4AF > C2S
• Order according to rate of hydration – C4AF > C3A > C3S > C2S
• Heat of hydration is measured using calorimeter.
➢ Requirement of water
• 23 % water by weight of cement is required to start the process of heat of hydration
and 38 % water by weight of cement is required to finish the process completely.
• 23 % water is for hydration of (C3S, C2S) and 15 % water is required for filling the
void.
• Generally, cement absorbs 2 % of hygroscopic water, but if it absorbs 5% of
hygroscopic water then the cement becomes useless.
