3. Ordinary Portland Cement (OPC)
• Most common cement in use
• About 70% of all cement used in India
• In modern Construction, higher grade cement is most popular;
• Higher grade OPC is little costlier than low grade OPC;
• But 10-20 % savings in cement consumption
Uses at general construction when there is no
exposure to sulphates
4. Rapid Hardening Cement (RHC)
• Develops strength rapidly;
• Also known as High Early Strength Cement;
• Rate of setting same as OPC;
• Strength of RHC at 3 days = Strength of OPC at 7 days
• Increased rate of gain of strength of RHC is achieved by higher C3S
content and finer grinding of clinkers;
• In pre-febricated concrete construction;
• For repair of road work;
• Formwork is required to remove early for other use;
• In cold weather concreting;
• Wall sealing
5. Extra Rapid Hardening Cement
• RHC + Calcium chlorides;
• Calcium chlorides should not be exceed 2% ;
• Concrete made by ERHC should be transported, placed, compacted
and finished within 20 minutes;
• Store in cold weathering and expiry date is 1 month;
• Large quantity of heat is evolved;
• Strength of ERHC is 25% higher than RHC at 1 or 2 days
• 10 to 20% higher at 7 days.
• Strength is nearly same at 90 days.
• Suitable for cold weathering;
• Suitable where a very high early strength is required;
• Not recommended for pre-stress concrete construction
6. Quick Setting Cement
• The name indicates sets very early.
• The early setting property is brought out by reducing the gypsum
content at the time of clinker grinding.
• This cement is required to be mixed, placed and compacted very early.
• It is used mostly in under water construction where pumping is
involved.
• Use of quick setting cement in such conditions reduces the pumping
time and makes it economical.
• Quick setting cement may also find its use in some typical grouting
operations.
• Under water construction;
• Grouting operations
7. Low Heat Cement
• Hydration of cement is an exothermic action which produces large quantity
of heat during hydration.
• A low-heat evolution is achieved by reducing the contents of C3S and C3A
which are the compounds evolving the maximum heat of hydration and
increasing C2S.
• A reduction of temperature will retard the chemical action of hardening and so
further restrict the rate of evolution of heat.
• The rate of evolution of heat will, therefore, be less and evolution of heat will
extend over a longer period. Therefore, the feature of low-heat cement is a slow
rate of gain of strength.
• 7 days — not more than 65 calories per gm.
• 28 days — not more than 75 calories per gm.
• The specific surface of low heat cement as found out by air-permeability
method is not less than 3200 sq. cm/gm. The 7 days strength of low heat
cement is not less than 16 Mpa in contrast to 22 MPa in the case of ordinary
Portland cement. Other properties, such as setting time and soundness are same
as that of ordinary Portland cement.
8. Uses of low heat cement
• Mass concrete constructions;
• Hot weather concreting;
• Where there is necessary to produce resistance to sulphate
attack
9. Sulphate Resisting Cement
• OPC is Susceptible to the attack of sulphate;
• Sulphate + Calcium hydroxide = Calcium Sulphate (Gypsum);
• Sulphate + Calcium Aluminate = Calcium sulphoaluminate;
• Result in expansion;
• Expansion will lead to crack in concrete;
• Known as Sulphate attack.
• Similar to OPC except the quantity of C3A is about 5 %.
Volume is 227% more than the volume of Original aluminates
• Marine structure;
• Sewage treatment plant and chemical factory;
• RCC pipes;
• Foundation and basement where soil with sulphate
10. Super Sulphated Cement
• Super-sulphated cement has a low heat of hydration of about 40-45 calories/gm
at 7 days and 45-50 at 28 days.
• This cement has high sulphate resistance.
Well granulated slag (80 To 85%) + Hard burnt Gypsum (10 to 15%) + Portland
cement (1 to 2%) = Super Sulphated Cement
• Specific surface = 3500 to 5000 Sq cm per gram
• Initial setting time 2.5 to 4 hours
• Final Setting time 4.5 to 7 hours
• The product is ground finer than that of Portland cement.
• Marine structure;
• Sewage treatment plant and chemical factory;
• RCC pipes;
• Foundation and basement where chemically aggressive condition
11. Portland Pozzolona Cement
• Addition of Pozzolona does not contribute to the strength at early stage, but it
gives later strength to those of OPC.
OPC Clinkers + Pozzolanic material (15 to 35%) such as flyash
and calcined clay
• C3S and C2S produce calcium hydroxide which is useless;
• If it is converted into useful cementitious product, it will
improve quality of concrete.
Ca(OH)2 + Flyash or Calcined clay + water = C-S-H (Gel)
• Marine structure;
• Plastering or mortar work;
• Hydraulic structure;
• Mass Concrete Strructure
12. Advantages of PPC
• Economical;
• Quality such as durability improved;
• Generate low heat of hydration;
• As the flyash is finer and lower density, the bulk volume of 50 kg
bag is slightly more than OPC. PPC gives more volume of mortar
than OPC
13. Continue…
Advantages of PPC
(a ) In PPC, costly clinker is replaced by cheaper pozzolanic material - Hence
economical.
(b ) Soluble calcium hydroxide is converted into insoluble cementitious products
resulting in improvement of permeability. Hence it offers, good durability
characteristics, particularly in hydraulic structures and marine construction.
(c) PPC consumes calcium hydroxide and does not produce calcium hydroxide as
much as that of OPC.
(d) It generates reduced heat of hydration and that too at a low rate.
(e) PPC being finer than OPC and also due to pozzolanic action, it improves the
pore size distribution and also reduces the microcracks at the transition zone.
(g) As the flyash is finer and of lower density, the bulk volume of 50 kg bag is
slightly more than OPC. Therefore, PPC gives more volume of mortar than OPC.
(h) The long term strength of PPC beyond a couple of months is higher than
OPC if enough moisture is available for continued pozzolanic action.
14. Portland Slag Cement
Advantages
– Better resistance to chloride, soils and water having excessive amount
of sulphate or alkalies, acidic water.
– Low heat of hydration and low permeability;
– Refinement of pore structure;
Portland Cement Clinker + Gypsum + Granulated Blast Furnace slag (25 to 65%)
Blast furnace Slag is waste produce consisting of lime + Silica + Alumina.
Cement should not be used in cold weather as the low heat of hydration and low
rate of strength development
• Uses in Mass Concrete work;
• For marine works
15. Coloured Cement (White Cement)
• Whiteness of white cement measured by ISI Scale should not be less than 70%;
• Also measured by Hunters scale (generally 90% is preferable)
OPC greyish colour is due to iron oxide
Manufacture of White cement is same like OPC; only Iron oxide is in limited %
(Less than 1% iron oxide) and Particular limestone from Jodhpur is required.
Portland cement + Pigment
• Uses in Filling the joints in Glazed tiles in
W.C., Bathroom, Kitchen etc.;
• To fill joints in flooring too.
16. Hydrophobic cement
• Water Repellent film prevents the entry of atmospheric moisture and
reduces the rate of deterioration of the cement during the long storage,
transport or under unfavorable condition.
• Film is broker out where cement and aggregate are mixed together.
Grinding ordinary Portland
cement clinker with water
repellent film-forming substance
such as oleic acid, and stearic acid.
17. Air Entraining Cement
Main Air Entraining Agents are:
– Alkali salt of wood resins;
– Calcium salts of glues and other proteins obtained in the treatment of animal hides;
– Calcium Lingosulphate derived from sulphite process in paper making;
– Synthetic detergents of the alkyl-aryl sulphonate type;
– Animal and vegetable fats, oils etc.;
– Bleaching powder;
– Hydrogen peroxide and Aluminium powder.
OPC clinkers + Air Entraining agent
Agent may be used in powder or in liquid forms to extent of 0.025 – 1 %
Used in produce light weight concrete
18. Masonry Cement (IS 3466 : 1988)
• Ordinary cement mortar, though good when compared to lime mortar
with respect to strength and setting properties, is inferior to lime
mortar with respect to workability, water retentivity, shrinkage
property and extensibility.
• It contains certain amount of air-entraining agent and mineral
admixtures to improve the plasticity and water retentivity.
• cement which is particularly made with such combination of
materials, which when used for making mortar, incorporates all the
good properties of lime mortar and discards all the not so ideal
properties of cement mortar.
19. Oil Well Cement
• Used in large depth;
• Used to seal off the annual space between steel casing and rock
strata and also seal off the fissures or cavities in the rock strata;
• Oil well cement are taken up to depth of 6000 mt.;
• The pressure required for that depth may go upto 1400 kg/cm2
Little C3A + Retarders in OPC+ admixture
20. Expansive Cement
• Concrete made with ordinary Portland cement shrinks while setting due to loss
of free water. Concrete also shrinks continuously for long time. This is known
as drying shrinkage.
• Cement used for grouting anchor bolts or grouting machine foundations or the
cement used in grouting the prestress concrete ducts, if shrinks, the purpose
for which the grout is used will be to some extent defeated.
• Generally, about 8-20 parts of the sulphoaluminate clinker are mixed with 100
parts of the Portland cement and 15 parts of the stabilizer.
• Grouting anchor bolts;
• Grouting machine foundation;
• Grouting prestress concrete ducts
21. High Alumina Cement
• Raw material in furnace and furnace is fire with Pulverised coal or oil with
a hot air blast at 1600 °C.
• Liquid cement in furnace will cooled. Then crushed it.
• Alumina: 39% and lime : 38%, Silica: 6%, Ferric oxide: 10%, Ferrous
oxide: 4%.
• It is slow setting but rapid hardening cement;
• Initial setting time: 4 hours and final setting time: 5 hours.
• It is resistant to chemical attack.
Fusing or Sintering a mixture of limestone and bauxite
Aluminous cement or Aluminate Cement
22. Disadvantages of High Alumina Cement
• More power consumption;
• Raw material Bauxite is costly;
• Very reactive;
• About 80% of ultimate strength is developed in 24 hours;
• Looses Strength at room temperature to 500° C.
23. Refractory Concrete
• High Alumina Cement is used to make Refractory cement with some
Admixture;
• Refractory cement is not loosing strength at room temperature.
Application:
• Foundations of all type of Furnaces;
• Ordinary furnaces (Kiln);
• Refractory mortar
24. Concrete Sleeper Grade Cement
• Minimum Strength at 1 day = 22 Mpa
• At 7 days = 33 Mpa
High strength cement manufacture as per specification laid down by Ministry
of Indian Railway under IRS-T 40: 1985.
Only use in Railway sleepers.
Very fine powder with C3S content. No accelerator agents are added.
25. Water proof cement
OPC + Waterproofing compounds like Calcium Stearate,
Aluminum Stearate and Gypsum with tannic acid
Materials are added at the time of clinkers grinding
Used in water proofing for terraces, water
tanks, w.c., Bathrooms.
26. Rediset Cement
• Associated Cement Company (ACC) of India have developed a cement,
which could Yield High strength in a matter of hours, without any
retrogression of strength; it is Rediset cement.
• Achieved by using admixtures.
• Initial setting time 8 to 10 minutes; and liberates more heat of hydration;
Application
• Repairs of concrete roads and
Pavements;
• Construction between tides;
• palletisation of iron ore
27. Very High strength Cement
1. High Early Strength Cement: this can be achieved by using Lithium salts
as accelerators; it gives very high early strength with marginal reduction of
later strength;
2. Magnesium Phosphate Cement (MPC): Central Road Research Institute
(CRRI) has developed MPC. Dead burnt Magnesite + fine aggregate
mixed with crystalline mono ammonium phosphate.
3. Pyrament Cement: Developed in USA; no chloride; use of blended
hydraulic product.
Cement of high strength required for repairs of runways,
launching pads, expressway pavement repairs;
