Thread by @drprashantmish6

Some Gyan on Cement ( all copy paste(civilread.com)
Cement is primarily characterized into two types:-
1Hydraulic cement
2Non-hydraulic cement.
Hydraulic cement:
The cement which hardens in the presence of water because of Hydration

This type of cement can also harden in underwater. Portland cement is the best example for hydraulic cement.
Non Hydraulic cement:
The cement which doesn’t harden underwater is called non-hydraulic cement.

This type of cement hardens when it reacts with the atmospheric carbon dioxide (carbonation). This cement is resistant to attack by chemicals after setting. Non-hydraulic cement is manufactured using non-hydraulic lime, gypsum plasters and oxychloride, which has liquid properties

14 Different types of cement :-
1. Ordinary Portland Cement
most common cement which is extensively used. It has good resistance to cracking and dry shrinkage but less resistance to chemical ,it is not suitable for the construction work which is exposed to sulphates in the soil.

2. Rapid Hardening cement:
Rapid hardening cement is very similar to ordinary Portland cement (OPC). The early strength is achieved by adding excessive C3S in the mix and by lowering the C2S content in the cement.

this type of cement is used where there is a need for high early strength. Ex. Pavements, busiest roadways
The strength of Rapid Hardening cement at age of 3 days is almost same as the 7 days strength of Ordinary Portland cement

This type of cement is not used for massive concrete constructions.

3. Low heat portland cement: –
This type of cement is manufactured by lowering the C3S content and increasing the C2S content. It possesses less compressive strength than ordinary Portland cement. It has less lime content than OPC.

This type of cement is mostly used in the construction of retaining walls and it is strictly not suitable for thin concrete structures.

4. Sulphate Resisting Portland Cement:-
It is manufactured by keeping the percentage of C3A below 5%. It is used where the structure is prone to severe sulphate attacks(alkaline conditions) such as construction in the foundation of soil, marine conditions, sewage treatment tanks.

5. High alumina Cement:-
This type of cement has rich alumina content about 35% which helps in gaining ultimate high strength within a short period. This type of cement is used where a structure is subjected to the action of sea water, chemical plants and furnaces.

6. Blast furnace slag cement:-
This type of cement is cheaper than Ordinary Portland cement. it is manufactured by intergrinding of OPC clinker and blast furnace slag. Blast furnace slag cement develops low heat of hydration and has less early strength.

7. Coloured Cement:-
This type of cement is also known as Colcrete. It is manufactured by adding coloring pigment to the OPC. it is used in joining tiles.

8. Pozzolana cement :-
The pozzolana is a material which is formed due to the volcanic eruptions. It is a siliceous material having about 80% clay in ,it is manufactured by mixing 30% of pozzolana to Ordinary Portland cement clinkers.

This type of cement is used in construction of dams and weirs.
9. Air-entraining cement:-
This type of cement is manufactured by adding 0.025–0.1% of air entraining agents to the ordinary Portland cement clinker.

Air entraining agents are generally made up of wood resins, calcium agents, vegetable oils and animal fats.

10. Hydrophobic cement:-
This type of cement is manufactured by grinding ordinary Portland cement clinker with water oleic acid or stearic acid. These acids forms as a water repellent film around the cement particle which increases the shelf life of cement.

The formed around each grain of cement reduces the rate of deterioration of the cement during long storage, transport, or under unfavourable conditions.

11. Expansive cement:-
This type of cement is manufactured by adding stabilizer which stabilizes the cement to expand. This can be achieved by adding 8-20% of sulphoaluminate & 15% of stabilizer to the ordinary Portland cement clinker.

Concrete made up of OPC shrinks while setting due to loss of free water. Concrete also shrinks continuously for a long time. Cement used for grouting should not shrink or change volume for this,. the expansive cement doesn’t show any volume change after hardening.

12. White Cement:-
This type of cement is obtained by lowering the iron oxide content in the Ordinary Portland cement. The strength and durability is same as OPC. This type of cement is used for joining tiles and other interior works.

13. Waterproof portland cement:-
This type of cement is manufactured by adding small percentages of metal sereates in OPC during grinding. This type of cement is used in foundations, water tanks & other water retaining structures.

14. Oil-well Cement:-
In order to extract oil from the stratified sedimentary rocks, Oil wells are dug to a greater depth. For safe pumping out of extracted oil steel casing is inserted.

It is likely that if oil is struck, oil or gas may escape through the space between the rock formation and steel casing. To fill this space Oil well cement is used. Oil well cement is manufactured by adding retarders (Starches or cellular products) to Ordinary Portland cement.

Cement manufacturing process

Clinker is a nodular material produced in the kilning stage during the production of cement and is used as the binder in many cement products. The lumps or nodules of clinker are usually of diameter 3-25 mm and dark grey in color.

Clinker is produced by heating limestone and clay to the point of liquefaction at about 1400°C-1500°C in the rotary kiln. Clinker, when added with gypsum (to control the setting properties of cement and ensure compressive strength) and ground finely, produces cement

Clinker can be stored for long periods of time in a dry condition without degradation of quality, hence it is traded internationally and used by cement manufacturers when raw materials are found to be scarce or unavailable.

Cement sector of india -
-Of the total capacity, 98% lies with private
sector and the rest with public sector.
- The top 20 companies account for around
70% of the total production.

-India’s overall cement
production capacity was nearly
545 million tonnes (MT) in
FY20 and accounted for over
8% of the global installed
capacity in FY20.
- India is the world’s secondlargest cement producer.--

Of the total 210 large cement
plants in India, 77 are situated in
the states of Andhra Pradesh,
Rajasthan & Tamil Nadu.

Top cement producers in india

cement production and consumption in different regions

Installed capacity in different regions

NTPC Ltd.are
collaborating with cement manufacturers (such
as Ultratech Cement, Rajshree Cement, Dalmia
Cement and ACC plants) across the country to
supply fly ash. This also helps achieve 100%
utilisation of the by-product (fly ash) produced
during power generatio

The Government of India has decided
to adopt cement instead of bitumen for
the construction of all new road
projects on the grounds that cement is
more durable & cheaper to maintain
than bitumen in the long run

How companies are working to reduce cost of production

Growth Drivers for Cement industry --
--The demand of Cement industry is expected to achieve 550-600 million tonnes per annum constantly by 2025 because of the
expanding requests of different divisions i.e. housing, commercial construction and industrial construction.

Housing and Real Estate
- Government initiatives like Housing for All will push demand in the
sector.
- Real estate market in India is expected to reach US$ 1 trillion by 2023.
-Strong growth in rural housing and low-cost housing to amplify demand.

Public Infrastructure
- As per Union Budget 2019-20, the Government is expected to upgrade 1,25,000 kms of road length over the next five years under NIP
. Union Budget 2021-22, the government approved an outlay of Rs. 1,18,101 crore (US$ 16.22 billion) for the Ministry of Road

Transport and Highways.
 Government announcements in November–December 2020 regarding
key infrastructure projects such as National Highway projects in Nagaland (worth US$ 560.88 million), Rajasthan (worth US$ 1.14 billion), Karnataka (worth US$ 1.49 billion)

and Telangana (worth US$
1.80 billion).
 As per the Union Budget 2021-22, National Infrastructure Pipeline
(NIP) expanded to 7,400 projects from 6,835 projects.
 Government of India’s push with Smart Cities Mission and AMRUT.

Industrial Development
- Strong economic growth is expected to lead to growth of the industrial
sector and in turn increase in demand in the long run.
-Cement demand in different sector

@threader_app compile