Types of cement and Test of cement

*Types Of Cement:-

1.     1.Ordinary Portland Cement (OPC):-

·       OPC -33 (IS:269-2015)
·       OPC -43 (IS:8112-1989)
·       OPC -53 (IS:12269-1987)
·       IST (Initial Setting Time)-30 minutes
·       FST (Final Setting Time)-600 minutes
·       OPC -33 used in small structures
·       OPC -43 used in normal structures like houses etc.
·       OPC -53 uses in large structures/precast structures like Bridges, Griders etc.

2.    2. Rapid Hardening Cement(IS:8041):-

·       More C3S and less C2S as compared to OPC.
·       10% more cost than OPC.
·       Not used in mass concrete & it produce Large Shrinkage.
·       RHC attains same strength in 1 day which an OPC attains in 3 days with same w/c (water              content).
·       It is suitable for repair of roads, bridges etc.
·       IST-10 minutes.
·       FST-10 hours.
·       Compressive Strength for one day is 16 N/mm².

3.    3. Extra Rapid Hardening Cement:-

·       Rapid Hardening Cement+2% CaCl2 (also called as calcium chloride cement).
·       1^st day strength – 25% More than OPC.
·       7^th day strength – 20% More than OPC.
·       Used in cold regions for repair works.

4.    4. High Alumina Cement(IS:6452):-

·       In High Alumina Cement there is C3A compound is not present.
·       Acid and Sulphate attack is less.
·       Composition- (Bauxite-40%, Lime-40%, Iron Oxide-15%, Magnesia-5%).
·       IST-3.5-4 hours.
·       FST-5-5.5 hours
·       It is used for refractory concrete, industries & used widely in Precasting.
·       Particularly suitable to sea & under water work.

5.     5.Low Heat Portland Cement:-

·       Low C3S & C3A and more content of C2S.
·       IST-1 hour.
·       FST-10 hours.
·       Acid & Sulphate attack is less.
·       It is used in mass concrete work.
·       Rate of development strength is low but ultimate strength is sam,e.
·       Heat of Hydration 272-314 KJ/Kg.

6.     6.Quick Setting Cement:-

·         In this cement the amount of gypsum is reduced or removed.
·         It is also called as Fine Grounded OPC.
·         IST-5 minutes.
·         FST-30 minutes.
·         Used in under water concreting.

7.     7.Coloured Portland Cement and White Cement(IS:8042):-

·         The cement which is free from iron oxide (Fe2O3).

·         Added White Chalk and China Clay.

·         These are used for making Terrazzo Flooring, ornamental works & casting stones.

·         Hunter scale is used for checking the whiteness of cement.

·          90% strength attains with the help of Sodium Alumino Ferrate.

·         5-10% colouring pigment added before grinding.

8.    8. Super Sulphated Portland Cement:-

·         Composition (80-85% Granulated slag + 10-15% Calcium Sulphate + 5% Portland Cement Clinker).
·         It is resistant to sulphate attack. And highly resistant to sea water.
·         It should not be used with any admixture.

9.     9.Portland Pozzolana Cement (IS:1489 part-1):-

·         OPC+10-30% of fly ash.
·         It is used in marine work.
·         Free lime is removed hence , resistance to chemical attack increases.
·         Pozzolana increases impermeability & water retaining capacity of concrete.
·         Pozzolana has no cementing property in itself but when it combines with lime, it provides a stable lime pozzolana compound which has cementious property.
·         The addition of pozzolana to concrete results in :-

a)     Improvement in durability by reducing permeability.

b)     Increase in workability of concrete.

c)      Reduction in shrinkage.

d)     Reduction in segregation & bleeding of concrete.

       10. Portland Slag Cement:-

·         Composition (Portland Cement + Granulated Blast Slag Furnace Slag + Gypsum).
·         High Sulphate Resistant.
·         It is used in mass concreting.

11.Water Repellant or Hydrophobic Cement:-

·         OPC + fractions os olic acid, stearic acid, or pentachlorophenol.
·         Suitable for basement & making water tight structures.

     12.Air Entraining Cement:-

·         OPC = Vinsol resin or vegetable fats of oils & fatty acids.
·         Small amount (0.1%) by weight of an air entraining agent.

 

Minimum Specified Strength in N/mm²
Type/Days	1 Day	3 Days	7 Days	28 Days
OPC (33 grade)	----------	16	22	33
Portland Pozzolana	--------	-------	22	33
Low Heat Portland	--------	10	16	33

 

*Types Of Cement Tests:-

Physical Tests:-

1.     1.Fineness Test:-

·        It is the measure of mean size of grain in it.
·        With increase in fineness, the early development of strength is enchanced but the ultimate strength is not affected.
·        Setting time decrease with increase in the fineness.

  

2.    2. Consistency :-

·        Amount of water used to make paste of normally consistency.
·        It is about 30% generally.
·        It is the percentage of water required for the cement paste.
·        The viscosity of which will be such that Vicat’s plunger penetrates upto 5 to 7 mm from bottom (33 to 35 mm from top) of  Vicat’s mould.

 

*Diameter length & shape of Vicat apparatus for different test.

S.No.	Types of Test	Diameter or size	Length	Shape
1.	Initial setting time	1 mm of square needle	Upto 50 mm & 40mm	Square needle
2.	Final setting time	5 mm	Upto 50 mm & 40mm	Annular Ring
3.	Consistency	10 mm	Upto 50 mm & 40mm	Solid circular

 

                         

3.    3. Initial & Final Setting Time:-

Initial Setting Time	Final Setting Time
·         It is possible to remix cement paste during this period.	·        Annular collar replaces square needle.
·        300 gm cement + 0.85 P of water (consistency)	·        Needle makes an impression but collar fails to do so.
·        1 mm2 square needle penetrates by 33-35 from top.
·        IST for OPC, RHC is 30 minutes.	·        FST for OPC, RHC – 10 hours.
·        IST for low heat cement – 1 hour.	·        FST for LHC – 10 hours.
·        IST for  High alumina cement –  (3.5-4) hours.	·        FST for High alumina cement –  (5-5.5) hours.

 

4.     4.Soundness Test:-

·         Due to presence of lime and magnesia soundness occurs.
·         Soundness test is done to detect change in volume after setting.
·         Two methods are adopted for soundness test. 1. Le-Chatelier’s method, 2. Auto clave Test

Le-Chatelier’s method	Auto clave Test
·         Measures soundness due to lime.	·         Measures soundness due to lime and magnesia.
·         100 gm of cement  +0.78 P (consistency)	·         100 gm of cement  +0.78 P (consistency)
·         Result is given in “mm”.	·         Result is given in “%age”.

 

*Le-Chatelier’s method:-

 

·         Size of hollow cylindrical  mould is 30*30 mm.
·         Both the ends of mould are covered with the glass plates.
·         And the mould is filled with the cement paste of 0.78 P consistency.
·         Two strips are inserted in the cement paste. 
·         After 24 hours measures the gap b\w the strips.
·         Let the gap is L1.
·         And after it the cylinder is dipped in the boiled water for 3 hours.
·         And cool down it for ½ hour.
·         And then again measure the gap b\w the strips.
·         Let the gap is L2.
·         Then the Soundness value is (L2-L1).
·          The soundness value for the OPC, RHC and low heat cement is ≯10mm.
·         The soundness value for High Alumina and supersulphated cement is 5mm.

 

*Auto clave Test:-

·        The size of the rectangular mould is 25*25*25 cm.
·        Fill it with cement paste of consistency 0.78 P.
·        After 24 hours measure the length of the mould suppose it is L1.
·        Now Steam saturation of the mould is done with 1.2 N/mm² to 2.1 N/mm² for 30 minutes.
·        After this process the mould is dipped in water of temperature 90° C for ½ hour.
·        And cool down it for ½ hour.
·        And after it again measures the length of mould suppose it is L2.
·        Then the soundness value is (L2-L1).
·        For any type of cement in auto clave test the soundness value is ≯.8%.

 

5.     5.Strength Test:-

                         *Special Points:-

·        The size of concrete cube is 150*150 mm.
·        Heat of Hydration is measured by Calorimeter.
·        Specific gravity is measured by the Le-Chatelier’s flask.
·        Specific Gravity of OPC is 3.15.

Time	OPC 33 N/mm²	OPC 43 N/mm²	OPC 53 N/mm²	LHC N/mm²
3 days	16	23	27	10
7 days	22	33	37	16
28 days	33	43	53	35