Ordinary Portland Cement (OPC):
·Extensively being used in general construction where corrosive
environment/ sulphur is not present & the special property of cement is not
required.
Normally available in three
different grade-33grade, 43grade & 53grade.
Sulphate Resisting Cement:
·Manufactured with low C3A content
(<5%)& comparatively low C4AF to prevent the sulphte attack reaction.
· Used where the environment (groundwater/soil ) is corrosive & sulphur attack is present.
Normally used in foundations, buried
pipelines & marine environments.
Rapid Hardening Cement:
· Similar to OPC, but ground finer.
·High C3S and low C2S content is
maintained to achieve early strength.
Producing more heat of hydration creates problems in mass concreting.
Can be used where high early strength is desirable Eg,
Prefabrication, road repair, and cold weather.
Extra Rapid hardening Cement:
·Manufactured with intergrinding
Rapid hardening cement with calcium chloride (CaCl2)< 2%.
Produce very high heat of
hydration.
Can be used where very fast
hardening is desirable.
·In concreting mixing, transportation, placing & finishing
needs to be done within 20min.
Storage of this type of cement
shall not be greater than 1 month.
Low-heat Cement:
·Manufactured with low C3A &
C3S and increased C2S.
·Ideal for mass concreting where low heat is desirable.
·Heat of hydration for
7days<65Cal/gm and for 28days< 75Cal/gm.
Super-sulphate Cement:
·Manufactured with granulated slag (80-85%) + hard burnt gypsum
(10-15%)+OPC clinker (5%)
Used where high sulphate resistance is desirable.
·Produce low heat of hydration.
·Used where environment (ground water/soil ) is highly corrosive
& sever sulphur attack is present.
Portland Slag Cement:
Manufacture intergrinding OPC clinker + gypsum + blast furnance
slag (25-65%).
Slag need to be the ground granulated blast furnance slag (GGBS),
presence crystalline slag cause low quality cement.
Produce low heat of hydration,
making ideal for mass concreting.
Better corrosion resistance.
But have slow strength development.
Portland Pozzolana Cement.
·Manufactured with intimate blending of OPC cement & fine
pozzolona.
·Pozzolona content may varies from 15-35%.
This type of cement gives low heat of hydration & better
corrosion resistance.
·But strength gain is also slower
& requires more curing. Ideal for hydraulic structure.
Flyash, Silica fume is common
pozzolona material used.
Coloured Cement
Manufactured with high quality
limestone(96% CaCO3 & Fe203<0.07%) with very low iron oxide content.
·5-10% pigment is groung together with OPC clinker to produce
colour cement.
Hydrophobic Cement:
Manufactured with OPC Clinker +
water repellent film forming substance (Oleic acid/ Stearic acid / Calcium
Oleate).
Prevent the cement to react with environmental moisture thus can
be used with long storage & poor storage condition.
·The preventive film broken out in
mixing process of concreting, allowing cement particle for hydration.
Mortar Cement
·Manufactured to overcome the
drawback of OPC in terms of workability & water retainability for masonry
construction.
Air entraining agent and/or admixtures are mixed with cement to
achive better workability & water retainability.
Ideal for all type of mortar work.
