Slide 1: GOVERNMENT COLLEGE OF ENGG AURANGABAD AN AUTONOMUS INSTITUTE OF GOVT. OF MAHARASHTRA IN PURSUIT OF GLOBAL COMPETITIVENESS CEMENT : CEMENT Created BY:-
Nikhil Pakwanne CEMENT : CEMENT Cement is a Building material obtained by burning and crushing of powder form , homogeneous and well proportioned mixture of lime (calcareous) and clay (argillaceous material). Chemicals and material : Chemicals and material Tri-calcium silicate (Ca)
Tetra-calcium alumino ferrite
Soda and Potash
Free lime Manufacturing process of cement : Manufacturing process of cement Manufacturing of cement : Manufacturing of cement There are 3 steps of manufacturing of cement
Mixing of raw materials
1) Mixing of raw Material :-
clay and limestone are taken in appropriate proportion and mixed in dry and wet condition.
mixed material is heated about 1400 – 1600 Degree celcius and cooled by passing through coolers.
so material obtained (clinker) is ground in mill and 2 % to 4 % gypsum is added to control the setting time of cement Types of Cement : Types of Cement 1)Ordinary Portland cement
2)Portland Pozzolana Cement
3)Sulphate Resisting Cement
6)Very high strength cement
7)Rapid Hardening Cement
8) Portland Slag Cement
10)Oil Well Cement Ordinary Portland Cement (is 269:1989) : Ordinary Portland Cement (is 269:1989) Although there are many types of Cement , about 80 -90% of total production is of Ordinary Portland Cement (OPC) only.
OPC is classified in three types of grades depending upon strength of cement as
Faster rate of development of strength
Offers 10-20 % savings in cement consumption
33 grade cement is almost out of the market
The manufacture of OPC is decreasing in view of popularity of blended cement on account of lower energy consumption, environmental pollution. Portland Pozzolana Cement : Portland Pozzolana Cement It is manufactured by intergrinding of OPC clinker with 10-25% of pozzolanic material
PPC produces heat of hydration and offer greater resistance to the attack of aggressive water than OPC.
PPC can generally be used where OPC is usable
rate of development of strength unto 7 days
It is economical
It offers durability charecteristics in marine & hydraulic structures
Strength of PPC is higher than OPC Coloured cement (is 8042-1989) : Coloured cement (is 8042-1989) For manufacturing of this cement ,white or grey portland cement is used as base
Use of white cement is costly while using grey portland cement only red & brown cement can be produced
Consists of PPC with 5-10% of pigment
For manufacture of white portland cement required limestone is only available around Jodhpur(Rajasthan)
White cement is ground finer than grey cement Rapid Hardening Cement (is 8041-1990) : Rapid Hardening Cement (is 8041-1990) This cement develops higher rate of development of strength
-Road repair works
-In pre-fabricated concrete construction
-In cold weather concrete Storage of cement : Storage of cement Water proof mesonry walls should be provided.
Leak proof roof with water proof cover should be provided.
Ground should be drained away to prevent from rain water Storage of cement bags : Storage of cement bags Bags should not be allowed to directly rest on the walls.
Not more than 15 bags be piled over the other.
If cement is to be stored in mansoon or for long period piles should be covered by polythene sheet. Field Tests for cement : Field Tests for cement Cement should be of uniform color.
When small sample of cement is rubbed between fingers ,it should feel smooth and cool.
There should no lumps in the cement. Laboratory tests of cement : Laboratory tests of cement 1)Fineness :-
This test is varified by using I.S. sieve No.9.
-now gentle sieving is done for fifteen minutes.
-The residue left is measured this should not be exceed 10 % by weight of the sample of the cement.
This is a test sonducted to estimate quantity
of water to be mixed with cement.
3) Soundness of cement ;-
Due to excess of lime in the cement expansion of cement occurs, that should be minimized. Slide 16: 4)Setting time :-
The object of this test is to make distinction between normal setting time and final setting time. This test can be conducted by using Vicat apparatus. References : References S.Ramamrutham ,Basics of civil Engineering,Dhanpat rai publishing company,New Delhi.
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