05-26-2022, 09:39 AM
ECONOMIC USAGE OF HIGH QUALITY CEMENT
Ambuja Technical Literature Series -1
In India the cement industry underwent a number of changes and reforms mainly to suit the Government policies and the economics of the manufacture. The annual cement production from nearly five million tonnes in 1952 shot upto over 54 million tonnes in 1993. The strict Government control for several years and rising costs of production resulted in production of poor quality of cement thereby resulting in poor quality of concrete structures.
Most monuments in India constructed using traditional building materials like wood, stone, marble, bricks, tiles and mortar have withstood the test of time. One of the main reasons for this is the use of good quality construction materials and the art of construction of the highest standards.
However following the development in advanced countries, we lost the art of construction. The economic approach took precedence over the scientific
approach and in the guise of being practical we forgot our theory.
The partial relaxation of Governmental control from March 1982 and a total relaxation of control after March 1989 revived the cement industry and resulted in its phenomenal growth. This resulted in a competitive market and cement manufactures had to improve their quality of cement as it was now a battle for survival of the best.
In the late eighties the dry process cement manufacturing took precedence over the more power oriented wet process. The cement manufacturers
modernised their old plants which were in various stages of obsolescence. The wet process plants were converted to more economical and efficient dry
process or semi-dry process plants.
This lead to the production of high quality cement. Several leading organisations diversified into cement manufacture and thereby created the much desired consumer oriented market with range of brands available at competitive prices. The 33 grade ordinary portland cement (18:269-1989) has virtually disappeared and is displaced by higher strength ordinary portland cements of 43 grade (IS: 8112-1989) and 53 grade (18:12269-1987).
2.0 SELECTION OF HIGH QUALITY CEMENT
With the advent of high quality cement in the market the consumer has a good product choice. However, the selection process of cement varies from consumer to consumer depending on financial constraints and I or other specification constraints.
It must be understood by the consumer that any good quality product is generally available at a higher price than a not so good quality product. It is therefore necessary for the consumer to know more about the benefits he gets when he selects a high quality cement and how best he can put to use such benefits considering both technical as well as the economical aspects.
A high strength cement although preferable to a lower strength cement may
not give a consumer the complete benefit unless and until it is giving consistently
high strength with minimum variation.
The high strength concrete if specified for any structure will also be more
desirable from durability point of view. It is often observed that low strength
concrete is mo.re vulnerable to environmental forces than high strength concrete
but at the same time high strength concrete too needs to be extremely carefully
batched, mixed, transported, placed, compacted and cured.
The durabiJity requirements of the structure are as important, if not more, as the
strength of the structure. A strong concrete may not result in high performance
concrete if the durability requirements are not complied with.
Selection of high quality cement can only mean a good beginning but it does
not assure the consumer of a final product which is the strong and durable
concrete structure. However, selection of poor quality cement or cement of
inconsistent quality is like taking a wrong step right at the beginning and will
certainly lead to poor quality concrete structure if not a disaster.
This write up gives the advantages and guidelines to the consumers for obtaining
the maximum possible benefit from high quality and high strength cement
produced by some of the leading cement manufacturers.
3.0 CEMENT STRENGTH CLASSIFICATION
A cement is generally identified either by its type or by its physical strength characteristics. The most commonly used cement in our country is the ordinary portland cement (OPC) and is generally branded as 33 grade (IS:269-1989), 43 grade (IS:8112-1989) or 53 grade (IS: 12269-1987) depending on the 28 days' compressive strength in N/mm2.
IS: 10262-1982, which gives the recommended guidelines for concrete mix design, has generally classified the cement gradewise from A to F, depending upon the 28 days strength as follows.
For More details download .....
Taken from Ambuja Technical Literature Series -1
Ambuja Technical Literature Series -1
In India the cement industry underwent a number of changes and reforms mainly to suit the Government policies and the economics of the manufacture. The annual cement production from nearly five million tonnes in 1952 shot upto over 54 million tonnes in 1993. The strict Government control for several years and rising costs of production resulted in production of poor quality of cement thereby resulting in poor quality of concrete structures.
Most monuments in India constructed using traditional building materials like wood, stone, marble, bricks, tiles and mortar have withstood the test of time. One of the main reasons for this is the use of good quality construction materials and the art of construction of the highest standards.
However following the development in advanced countries, we lost the art of construction. The economic approach took precedence over the scientific
approach and in the guise of being practical we forgot our theory.
The partial relaxation of Governmental control from March 1982 and a total relaxation of control after March 1989 revived the cement industry and resulted in its phenomenal growth. This resulted in a competitive market and cement manufactures had to improve their quality of cement as it was now a battle for survival of the best.
In the late eighties the dry process cement manufacturing took precedence over the more power oriented wet process. The cement manufacturers
modernised their old plants which were in various stages of obsolescence. The wet process plants were converted to more economical and efficient dry
process or semi-dry process plants.
This lead to the production of high quality cement. Several leading organisations diversified into cement manufacture and thereby created the much desired consumer oriented market with range of brands available at competitive prices. The 33 grade ordinary portland cement (18:269-1989) has virtually disappeared and is displaced by higher strength ordinary portland cements of 43 grade (IS: 8112-1989) and 53 grade (18:12269-1987).
2.0 SELECTION OF HIGH QUALITY CEMENT
With the advent of high quality cement in the market the consumer has a good product choice. However, the selection process of cement varies from consumer to consumer depending on financial constraints and I or other specification constraints.
It must be understood by the consumer that any good quality product is generally available at a higher price than a not so good quality product. It is therefore necessary for the consumer to know more about the benefits he gets when he selects a high quality cement and how best he can put to use such benefits considering both technical as well as the economical aspects.
A high strength cement although preferable to a lower strength cement may
not give a consumer the complete benefit unless and until it is giving consistently
high strength with minimum variation.
The high strength concrete if specified for any structure will also be more
desirable from durability point of view. It is often observed that low strength
concrete is mo.re vulnerable to environmental forces than high strength concrete
but at the same time high strength concrete too needs to be extremely carefully
batched, mixed, transported, placed, compacted and cured.
The durabiJity requirements of the structure are as important, if not more, as the
strength of the structure. A strong concrete may not result in high performance
concrete if the durability requirements are not complied with.
Selection of high quality cement can only mean a good beginning but it does
not assure the consumer of a final product which is the strong and durable
concrete structure. However, selection of poor quality cement or cement of
inconsistent quality is like taking a wrong step right at the beginning and will
certainly lead to poor quality concrete structure if not a disaster.
This write up gives the advantages and guidelines to the consumers for obtaining
the maximum possible benefit from high quality and high strength cement
produced by some of the leading cement manufacturers.
3.0 CEMENT STRENGTH CLASSIFICATION
A cement is generally identified either by its type or by its physical strength characteristics. The most commonly used cement in our country is the ordinary portland cement (OPC) and is generally branded as 33 grade (IS:269-1989), 43 grade (IS:8112-1989) or 53 grade (IS: 12269-1987) depending on the 28 days' compressive strength in N/mm2.
IS: 10262-1982, which gives the recommended guidelines for concrete mix design, has generally classified the cement gradewise from A to F, depending upon the 28 days strength as follows.
For More details download .....
Taken from Ambuja Technical Literature Series -1