With certificates of quality, weight, packing and loading issued by independent inspection agencies, we manufacture
and supply quality cement conforming to the following standards:
• China’s cement standard GB 175-2007 and clinker standard GB/T 21372-2008;
• American standard ASTM C-150 07;*
• European standard EN 197-1:2000;
• Russian standard GOST 30515-97.
A particular brand, country of origin, etc. are not factors which
influence or determine the quality and consistency of the cement
which is a big misconception on the side of the Buyers.
The sulfate and alkali contents of the cement clinker much affect
the quality of clinker hence of cement, the setting time and the
course of hardening.
33 grade – General Construction like plastering, finishing works etc.,
where high strength is not required.
43 grade – Useful for structural works, precast items etc, Strength
development is faster than 33 grade.
53 grade – Used for multi-story buildings, precast prestressed items,
bridges, tall structures. Develops very fast strength and speeds up
Important for the Buyers to know:
Cement bag should bear BIS Certification mark
• Grade of Cement –Means minimum compressive
strength of cement sand mortar cube at 28 days
strength when tested as per IS standards.
• Grade of concrete in an important criterion but
not the sole criteria to decide the quality of
• Durability of construction is the important factor.
• Important factors contributing to the durability are:
1. Type of cement
2. Design Of concrete mix
3. Placing compaction and curing of concrete
4. Subsequent maintenance and repairs.
5. Test Certificate from the supplier Compressive Strength - Capacity to bear loads, higher strength is preferred. Soundness - Indicates % expansion due to free lime& magnesia. Excessive expansion reduces durability of structure.
The cement with lower value is preferred. Chloride content & Alkali percentage - The upper limit prescribed by IS for chlorides is 0.05% and alkalis is 0.6%.
To control corrosion of steel a good quality of cement should have lower values.
Insoluble residue in cement - Non reactive substances in cement. IS specifies a limit of 2 to 4%. Excess indicates
adulteration. Loss on ignition – IS pacifies 4to 5% limit. Excess percentage indicates adulteration. Markings on the bag - Type, Grade, ISI,Mark, License No. , week of packing. A cement more than 90 days old from
the date of packing is required to be retested before use as per IS code requirement. Check For Adulteration – Cement gives a cool feeling when hand is inserted in the bag. OPC when dropped in a
bucket of water it settles down and no floating material is left on the surface.
Ideal Color of CEMENT – A good quality cement is greenish grey. Different types of cement for different applications – Desirable to construction foundations, sewage and water
works in Sulphate resistant cements , RCC in 43 or 53 OPC, Plastering and masonry works in PPC. It will optimize the
cost and improve the quality of construction.
The most important factors acting on the cement quality are the chemical composition of the raw materials and
the clinker, the effect of ferrioxide, S03’ alkali sand magnesia.! A similar importance is due to the way of burning,
to the kiln atmosphere, to the se-quence of clinker formation. Cooling and cement properties are strictly related.
The grinding fineness markedly affects the early strength. For Portland cements of high early strength, hydraulic
setting and hardening can be influenced by admixtures. AIumina cements rely on the formation of CA and CA2In
connection “with the hydration of alumina cements both the concrete porosity and the water! cement ratio has to
be kept at a minimum.
Cement is a finely ground inorganic material, which, when mixed with water, forms a paste which hardens by means
of hydration reactions and which, after hardening, retains its strength and stability even under water.
Portland cement (often referred to as OPC, from Ordinary Portland Cement) is the most
common type of cement in general use around the world because it is a basic ingredient
of concrete, mortar, stucco and most non-specialty grout. It is a fine powder produced by
grinding Portland cement clinker. Portland cement clinker is a hydraulic material which shall
consist of at least two-thirds by mass of calcium silicates (3CaO.SiO2 and 2CaO.SiO2), the
remainder consisting of aluminum- and iron-containing clinker phases and other compounds.
There are three fundamental stages in the production of Portland cement : (a) Preparation
of the raw mixture, (b) Production of the clinker, (c) Preparation of the cement Cement quality is typically assessed by its compressive
strength development in mortar and concrete. The
basis for this property is a well-burned clinker with
consistent chemical composition and free lime. The main
reason for the clinker free lime to change in situation
with stable kiln operation is variation in the chemical
composition of the kiln feed. This variation in chemical
composition is related to raw mix control and the
homogenization process. To ensure a constant quality of
the product and maintain a stable
and continuous operation of the
kiln, the attention must be paid
to storage and homogenization
of raw materials and kiln feed.
Due to variations in the kiln
feed chemical compositions that
affect its burn ability and the fuel
consumption. The raw materials for Portland cement production are the mixture (as fine
powder in the ‘Dry process’) of minerals containing
calcium oxide, silicon oxide, aluminum oxide, ferric
oxide, and magnesium oxide. The homogeneity of feed
chemical composition has an important relationship to
fuel consumption, kiln operation, clinker formation and
cement performance. In this regard an attempt made
to deals with the mixing of raw materials process and
estimation of composition of raw mill feed, kiln feed,
as well as formed clinker, which were done successfully
through various results obtained experimentally and
various steps have been taken to reduce these variations
in clinker quality Cement.
Portland cement is produced by grinding cement
clinker in association with gypsum (3-5 %) to specified
fineness depending on the requirements of the cement
consumers. Cement clinker is produced on large scale
by heating finely ground raw materials (Calcareous and Argillaceous materials) at very high temperature up to 1450 oC in rotary kilns. The materials that can be used in
cement industry as raw materials are listed in Table below;
Portland cement is the chief ingredient in
cement paste - the binding agent in Portland
cement concrete (PCC). It is a hydraulic cement
that, when combined with water, hardens into a
solid mass. Interspersed in an aggregate matrix
it forms PCC. As a material, Portland cement
has been used for well over 175 years and, from
an empirical perspective, its behavior is well
understood. The patent for Portland cement was
obtained in 1824 by Joseph Aspdin. Chemically,
however, Portland cement is a complex
substance whose mechanisms and interactions
have yet to be fully defined. The Portland Cement Association (PCA) provides the following precise definitions:
Hydraulic cement: Hydraulic binder, ie. a finely ground inorganic material, which, when mixed with water, forms a
paste which sets and hardens by means of hydration reactions and processes and which, after hardening, retains its
strength and stability even under water. Portland cement: An hydraulic cement composed primarily of hydraulic calcium silicates.
Today, Portland cement is the most widely used building material in the world with about 1.56 billion tones produced
each year. Annual global production of Portland cement concrete hovers around 3.8 million cubic meters (5 billion
cubic yards) per year as of 2004.
Portland cement types and their uses
Portland cement is hydraulic cement produced by
milling clinker, which includes calcium silicates, calcium
aluminates with calcium sulphate as an additive. Due
to the fact that its low cost and widespread availability
of its raw material, limestone, Portland cement one of
the materials widely used. In order to meet different
physical and chemical requirements for specific
purposes, such as durability and high-early strength,
different types of portland cement are manufactured.
American Society for Testing Materials (ASTM), and
European Standards (EN) exhibit some differences.
Portland Cement (American Standard Type) - Eight
types of cement are covered in ASTM C 150. These
types and brief descriptions of their uses are listed in
Portland Cement (European Standard Types) - EN
standards use two types of Portland cement: CEM I:
Portland Cement and CEM II: Composite-Portland
The process is consists of three stages: feeding, grinding, and separating.
Physical Properties of each type of cement include;
2. Setting time
4. Compressive strength
5. Heat of hydration
6. Loss of ignition
Summary about cement
Cement was first discovered by an English brick layer named Joseph
Aspdin in 1824. He called it Portland cement for the reason that the
cement he discovered resembled the limestone found in Portland.
The approximate composition of Portland cement is given below
Lime (CaO) 60 – 70% Silica (SiO2) 20 – 25% Alumina (Al2O3) 5 –
10% Ferric oxide (Fe2O3) 2 – 3 %
The raw materials used for the manufacture of Portland cement
are limestone (provides CaO) and clay (provides SiO2 , Al2O3 and
Fe2O3) which are finely powdered and then mixed in the ratio 3 : 1 by mass.
The mixture is again ground to a fine powder and water is added. The finely ground powder called slurry is heated
to 1773 K in a rotary kiln. On heating, lime, silica, alumina and ferric oxide react together and produces a mixture of
dicalcium silicate, tricalcium silicate and tricalcium aluminate called clinker. The clinker is cooled and a small amount
of gypsum (2 – 5%) is added to it, to delay the setting time of cement. The mixture of clinker and gypsum is then
ground to a fine powder which is called cement. It is stored in tall structures called silos. The cement is then packed
in water-proof bags and sold in markets.
When cement is mixed with water, it becomes hard over a period
of time. This is called setting of cement. Gypsum is often added
to Portland cement to prevent early hardening or “flash setting”,
allowing a longer working time.
What are Different Grades of Cement? The grade 43 and 53 in
cement mainly corresponds to the average compressive strength
attained after 28 days ( 6724 hours) in mega pascals (Mpa) of at
least three mortar cubes ( area of face 50 cm squared) composed
of one part cement, 3 parts of standard s and ( conforming to IS
650:1966) by mass and P/4 ( P is the percentage of water required
to produce a paste of standard consistency as per IS standard) +
3 percentage ( of combined mass of cement plus sand) of water ,
prepared, stored and tested in the manner described in methods
of physical test for hydraulic cement.
721 hr not less than 23 MPa for 43 grade, 27 MPa for 53 grade
1682 hrs not less than 33MPa for 43 grade, 37MPa for 53 grade
6724 hrs not less than 43MPa for 43 grade, 53 MPa for 53 grade.