Types of Cement |Testing of Cement | which type of cement use construction industry|Indian Standard Code|ASTM classification | सिमेंट चे विविध प्रकार | सिमेंट वरती केल्या जाणारे टेस्ट | कोणते सिमेंट वापरले पाहिजे आपण घर बांधताना ||By unique Civil Engineering
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| Types of Cement |
- Contents:-
! ASTM Classification.
! Ordinary Portland Cement.
! Rapid Hardening Cement.
! Extra Rapid Hardening Cement.
! Sulphate Resisting Cement.
! Portland Slag Cement (PSC).
! Quick Setting Cement.
! Super Sulphated Cement.
! Low Heat Cement.
! Portland Pozzolana Cement.
! Air-Entraining Cement.
! Coloured Cement (White Cement).
! Hydrophobic cement.
! Masonry Cement.
! Expansive Cement.
! IRS-T 40 Special Grade Cement.
! Oil-Well Cement.
! Rediset Cement.
! High Alumina Cement.
! Refractory Concrete.
! Very High Strength Cement.
! Fineness Test.
! Standard Consistency Test.
! Setting Time Test.
! Strength Test.
! Soundness Test.
! Heat of Hydration.
In the previous Blog/Post we have discussed various properties of Portland cement in general. 👈 Click Here
We have seen that cements exhibit different
properties and characteristics depending upon their chemical compositions. By changing the fineness of grinding or the oxide composition, cement can be made to exhibit different properties. In the past
continuous efforts were made to produce different kinds of cement, suitable for different situations by changing oxide composition and fineness of grinding. With the extensive use of cement, for widely varying conditions, the types of cement that
could be made only by varying the relative
proportions of the oxide compositions, were not found to be sufficient.
*Types of Cement:-
(A) Ordinary Portland Cement:-
(i) Ordinary Portland Cement
( 33 Grade–(IS 269: 1989)
(ii) Ordinary Portland Cement
(43 Grade– IS 8112: 1989)
(iii) Ordinary Portland Cement
( 53 Grade– IS 12269: 1987)
(B) Rapid Hardening Cement – IS 8041: 1990
(C) Extra Rapid Hardening Cement – –
(D) Sulphate Resisting Cement –
(IS 12330: 1988)
(E) Portland Slag Cement – (IS 455: 1989)
(F) Quick Setting Cement – –
(G) Super Sulphated Cement – IS 6909: 1990
(H) Low Heat Cement – IS 12600: 1989
(I) Portland Pozzolana Cement –
-IS 1489 (Part I) 1991 (fly ash based)
- IS 1489 (Part II) 1991 (calcined clay
based)
(J) Air Entraining Cement – –
(K) Coloured Cement: White Cement –
(IS 8042: 1989)
(L) Hydrophobic Cement – IS 8043: 1991
(M) Masonry Cement – IS 3466: 1988
(N) Expansive Cement – –
(O) Oil Well Cement – IS 8229: 1986
(P) Rediset Cement – –
(Q) Concrete Sleeper grade Cement –
( IRS-T 40: 1985)
(R) High Alumina Cement – IS 6452: 1989
- ASTM Classification:-
Before we discuss the above cements, for general information, it is necessary to see how Portland cement are classified under the ASTM (American Society for Testing Materials) standards. As per ASTM, cement is designated as Type I, Type II, Type III, Type IV, Type V and other minor types like Type IS, Type IP and Type IA IIA and IIIA.
Type I:-
For use in general concrete construction where the special properties specified for Types I, II, III, IV and V are not required (Ordinary Portland Cement).
Type II:-
For use in general concrete construction exposed to moderate sulphate action, or where moderate heat of hydration is required.
Type III
For use when high early strength is
required (Rapid Hardening Cement).
Type IV
For use when low heat of hydration is
required (Low Heat Cement).
Type V:-
For use when high sulphate resistance is
required (Sulphate Resisting Cement).
ASTM standard also have cement of the
type IS. This consist of an intimate and uniform blend of Portland Cement of type I and fine granulated slag. The slag content is between 25 and 70 per cent of the weight of Portland Blast-Furnace Slag Cement.
Type IP:-.
This consist of an intimate and uniform
blend of Portland Cement (or Portland Blast
Furnace Slag Cement) and fine pozzolana in
which the pozzolana content is between 15
and 40 per cent of the weight of the total cement.
Type IA, IIA and IIIA:-
These are type I, II or III cement in which air-entraining agent is interground where air-entrainment in concrete is desired.
1) Ordinary Portland Cement:-
Ordinary Portland cement (OPC) is by far the most important type of cement. All the
discussions that we have done in the previous chapter and most of the discussions that are going to be done in the coming chapters relate to OPC. Prior to 1987, there was only one grade of OPC which was governed by IS 269-1976. After 1987 higher grade cements were introduced in India. The OPC was classified into three grades, namely 33 grade, 43 grade and
53 grade depending upon the strength of the cement at 28 days when tested as per IS 4031-1988. If the 28 days strength is not less than 33N/mm2, it is called 33 grade cement, if the
strength is not less than 43N/mm2, it is called 43 grade cement, and if the strength is not less
then 53 N/mm2, it is called 53 grade cement. But the actual strength obtained by these
cements at the factory are much higher than the BIS specifications.
2) Rapid Hardening Cement (IS 8041–1990):-
This cement is similar to ordinary Portland cement. As the name indicates it develops
strength rapidly and as such it may be more appropriate to call it as high early strength
cement. It is pointed out that rapid hardening cement which develops higher rate of development of strength should not be confused with quick-setting cement which only sets quickly. Rapid hardening cement develops at the age of three days, the same strength as thatis expected of ordinary Portland cement at seven days.
3) Extra Rapid Hardening Cement:-
Extra rapid hardening cement is obtained by intergrinding calcium chloride with rapid hardening Portland cement. The normal addition of calcium chloride should not exceed 2 percent by weight of the rapid hardening cement. It is necessary that the concrete made by using extra rapid hardening cement should be transported, placed and compacted and finished
within about 20 minutes. It is also necessary that this cement should not be stored for more than a month.
Extra rapid hardening cement accelerates the setting and hardening process. A large
quantity of heat is evolved in a very short time after placing. The acceleration of setting,hardening and evolution of this large quantity of heat in the early period of hydration makes the cement very suitable for concreting in cold weather, The strength of extra rapid hardening cement is about 25 per cent higher than that of rapid hardening cement at one or two days
and 10–20 per cent higher at 7 days. The gain of strength will disappear with age and at 90 days the strength of extra rapid hardening cement or the ordinary portland cement may be nearly the same.
4) Sulphate Resisting Cement (IS 12330–1988):-
Ordinary Portland cement is susceptible to the attack of sulphates, in particular to the
action of magnesium sulphate. Sulphates react both with the free calcium hydroxide in set-cement to form calcium sulphate and with hydrate of calcium aluminate to form calcium sulphoaluminate, the volume of which is approximately 227% of the volume of the original aluminates. Their expansion within the frame work of hadened cement paste results in cracks and subsequent disruption. Solid sulphate do not attack the cement compound. Sulphates in solution permeate into hardened concrete and attack calcium hydroxide, hydrated calcium
aluminate and even hydrated silicate.
5) Portland Slag Cement (PSC) (IS 455–1989):-
Portland slag cement is obtained by mixing Portland cement clinker, gypsum and granulated blast furnace slag in suitable proportions and grinding the mixture to get a thorough and intimate mixture between the constituents. It may also be manufactured by separately grinding Portland cement clinker, gypsum and ground granulated blast furnace slag
and later mixing them intimately. The resultant product is a cement which has physical properties similar to those of ordinary Portland cement. In addition, it has low heat of hydration and is relatively better resistant to chlorides, soils and water containing excessive amount of sulphates or alkali metals, alumina and iron, as well as, to acidic waters, and therefore, this can be used for marine works with advantage.
6) Quick Setting Cement:-
This cement as the name indicates sets very early. The early setting property is brought
out by reducing the gypsum content at the time of clinker grinding. This cement is required to be mixed, placed and compacted very early. It is used mostly in under water construction where pumping is involved. Use of quick setting cement in such conditions reduces the pumping time and makes it economical. Quick setting cement may also find its use in some
typical grouting operations.
7)Super Sulphated Cement (IS 6909–1990):-
Super sulphated cement is manufactured by grinding together a mixture of 80-85 per
cent granulated slag, 10-15 per cent hard burnt gypsum, and about 5 per cent Portland cement clinker. The product is ground finer than that of Portland cement. Specific surface must not be less than 4000 cm2 per gm. The super-sulphated cement is extensively used in Belgium,where it is known as “ciment metallurgique sursulfate.” In France, it is known as “ciment sursulfate”.
This cement is rather more sensitive to deterioration during storage than Portland cement.Super-sulphated cement has a low heat of hydration of about 40-45 calories/gm at 7 days and 45-50 at 28 days.
8)Low Heat Cement (IS 12600-1989):-
It is well known that hydration of cement is an exothermic action which produces large quantity of heat during hydration. This aspect has been discussed in detail in Chapter 1. Formation of cracks in large body of concrete due to heat of hydration has focussed the attention of the concrete technologists to produce a kind of cement which produces less heat or the same
amount of heat, at a low rate during the hydration process. Cement having this property was developed in U.S.A. during 1930 for use in mass concrete construction, such as dams, where temperature rise by
the heat of hydration can become excessively large. A low-heat evolution is achieved by reducing the contents
of C3S and C3A which are the compounds evolving the maximum heat of hydration and increasing C2S. A reduction of temperature will retard the chemical action of hardening and so further restrict the rate of evolution of heat. The rate of evolution of heat will, therefore, be less and evolution of heat will extend over a longer period.
Therefore, the feature of low-heat cement is a slow rate of gain of strength. But the ultimate strength of low-heat cement is the same as that of ordinary Portland cement. As per the Indian Standard Specification the heat of hydration of low-heat Portland.
cement shall be as follows:-
7 days — not more than 65 calories per gm.
28 days — not more than 75 calories per gm.
9)Portland Pozzolana Cement (IS 1489–1991):-
The history of pozzolanic material goes back to Roman’s time. The descriptions and details of pozzolanic material will be dealt separately under the chapter ‘Admixtures’. However a brief description is given below.
Portland Pozzolana cement (PPC) is manufactured by the intergrinding of OPC clinker with 10 to 25 per cent of pozzolanic material (as per the latest amendment, it is 15 to 35%).A pozzolanic material is essentially a silicious or aluminous material which while in itself possessing no cementitious properties, which will, in finely divided form and in the presence
of water, react with calcium hydroxide, liberated in the hydration process, at ordinary temperature, to form compounds possessing cementitious properties. The pozzolanic materials generally used for manufacture of PPC are calcined clay (IS 1489 part 2 of 1991) or fly ash (IS
1489 part I of 1991). Fly ash is a waste material, generated in the thermal power station,when powdered coal is used as a fuel. These are collected in the electrostatic precipitator. (It is called pulverised fuel ash in UK). More information on fly ash as a mineral admixture is given in
TESTING OF CEMENT:-
Field Testing
Fineness Test
Sieve Test.
Air Permeability Method.
Strength Test.
Soundness Test.
Heat of Hydration.
Chemical Composition Test
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