What is the Difference between ppc cement and opc cement?
Cement is made by heating limestone (calcium
carbonate) with small quantities of other materials (such as clay) to 1450°C in
a kiln. The resulting hard substance, called 'clinker', is then ground with a
small amount of gypsum into a powder to make 'Cement', the most commonly used
type of cement. This cement is called Ordinary Portland Cement
Ordinary Portland Cement (OPC) is the most
common cement used in general concrete construction when there is no exposure
to sulphates in the soil or groundwater.
Portland cement is the most common type of
cement in general use around the world, used as a basic ingredient of concrete,
mortar, stucco, and most non-speciality grout. It was developed from other types
of hydraulic lime in England in the mid 19th century and usually originates
from limestone.
To retard the faster setting time of cement
resulted from (C3A) compound a percentage of raw gypsum (selenite) is added
during the grinding of the clinker.
Ordinary Portland cement (OPC-53, OPC-43,
OPC-33).
The 43 grade OPC is the most popular
general-purpose cement in India. The OPC can be used for following
applications:
·
General Civil
Engineering construction work
·
RCC works(preferably
where grade of concrete is up to M-30)
·
Pre-cast items such as
blocks, tiles, pipes etc
·
Asbestos products such
as sheets and pipes
·
Non-structural works
such as plastering, flooring etc.
Portland Pozzolana Cement (PPC)
The Portland Pozzolana Cement is a kind of
Blended Cement which is produced by either inter grinding of OPC clinker along
with gypsum and pozzolanic materials in certain proportions or grinding the OPC
clinker, gypsum and Pozzolanic materials separately and thoroughly blending
them in certain proportions.
Portland Pozzolana Cement also commonly
known as PPC cement. These
types of cement are manufactured by using pozzolanic materials as one of
the main ingredient. The percentage of pozzolanic material used in the
preparation should be between 10 to 30. If the percentage is exceeded, the
strength of cement is reduced.
Pozzolana is a natural or artificial material
containing silica in a reactive form. It may be further discussed as siliceous
or siliceous and aluminous material which in itself possesses little, or no
cementitious properties but will in finely divided form and in the presence of
moisture, chemically react with calcium hydroxide at ordinary temperature to
form compounds possessing cementitious properties. It is essential that
pozzolana be in a finely divided state as it is only then that silica can
combine with calcium hydroxide (liberated by the hydrating Portland cement) in
the presence of water to form stable calcium silicates which have cementitious
properties.
The pozzolanic materials commonly used are:
·
Volcanic ash
·
Calcined clay
·
Fly ash
·
Lica fumes
Comments
Post a Comment