CONSTRUCTION MATERIAL
RAVI KANT MITTAL
DEPARTMENT OF CIVIL ENGINEERING
ROOM NO. 2107
Email: ravimittalcivil@gmail.com
Mobile: 9887692025
01596-244090
Dr. Ravi Kant Mittal, BITS, Pilani
CEMENT
• 33 Grade ordinary Portland cement conforming to
IS 269 (OPC 33)
• 43 Grade ordinary Portland cement conforming to
IS 8112 (OPC 43)
• 53 Grade ordinary Portland cement conforming to
IS 12269 (OPC 53)
• Rapid hardening Portland cement conforming to
IS 8041
• Portland slag cement conforming to IS 455 (PSC)
Dr. Ravi Kant Mittal, BITS, Pilani
CEMENT
• Portland pozzolana cement (fly ash based)
conforming to IS 1489 (Part 1) (PPC)
• Portland pozzolana cement (calcined clay based)
conforming to IS 1489 (Part 2)
• Hydrophobic cement conforming to IS 8043
• Low heat Portland cement conforming to IS 12600
• Sulphate resisting Portland cement conforming to
IS 12330
• White cement conforming to IS 8042
Dr. Ravi Kant Mittal, BITS, Pilani
Main Constituents of Cement
•
•
•
•
Calcium (Ca)/ Lime(CaO) (Lime stone)
Silica (SiO2) (Sand)
Alumina (Al2O3)(Clay)
Iron oxide (Fe2O3) (Iron ore)
Dr. Ravi Kant Mittal, BITS, Pilani
Main Constituents of Cement
•
•
•
•
•
Lime /Calcium (CaO) (60-67%)
Silica (SiO2) (17-25%)
Alumina (Al2O3) (3-8%)
Iron oxide (Fe2O3) (0.5-0.6%)
Magnesia (MgO) (0.5- 4%)
• Soda and Potash alkalies (Na2O + K2O) (2 - 3.5%)
• Sulphar trioxide(SO3) (0.3-1.2)
Dr. Ravi Kant Mittal, BITS, Pilani
Dr. Ravi Kant Mittal, BITS, Pilani
Bogue Compound (R.H. Bogue)
• Tricalcium Silicate (3CaO.SiO2)
C3S
25 – 50%
• Dicalcium Silicate (2CaO.SiO2)
C2S
20 – 45%
• Tricalcium Aluminate (3CaO.Al2O3)
C3A
5 – 12%
• Tetra Calcium aluminao ferrite
(4CaO.Al2O3.Fe2O3)
C4AF
6 – 14%
Dr. Ravi Kant Mittal, BITS, Pilani
Hydration and Structure of
Cement Paste
• The chemical reactions of cement
components and water are collectively
called hydration.
• The two main types of components are the
silicates and the aluminates.
Dr. Ravi Kant Mittal, BITS, Pilani
• The reaction of cement compounds with water may
be separated into two main groups.
• The first stage is the aluminates with water
contributing to the high heat of hydration. The
added gypsum goes into solution to react with
tricalcium aluminate forming a product known as
ettringite.
• C3A + Gypsum + Water → Ettringite (tri-sulphate hydrate)
+ Heat
• As sulphate is depleted, ettringite is converted into
monosulphate.
• C3A +Ettringite + water → Monosulphoaluminate
• Responsible for setting action but makes only
small contribution to strength.
• C3A high value undesirable , due to maximum
heat generate
Dr. Ravi Kant Mittal, BITS, Pilani
• The silicates react with water to form
crystalline calcium hydroxide and a low
crystalline calcium silicate hydrate called
C-S-H gel.
• This structure has a typical gel porosity of
about 26 to 28% with a very high specific
surface (surface area per unit mass).
• The amount of water needed for full
hydration of cement is about 20 to 25% by
mass of cement.
.
Dr. Ravi Kant Mittal, BITS, Pilani
Dr. Ravi Kant Mittal, BITS, Pilani
• C3S hydrates quickly and responsible
for most of first seven days strength of
concrete.
• C2S starts contributing after 7 days,
responsible for long term strength.
Generates minimum heat.
Dr. Ravi Kant Mittal, BITS, Pilani
Dr. Ravi Kant Mittal, BITS, Pilani
b) Fineness
v Fineness of cement is a measure of the sizes particles of
cement.
v It is expressed in terms of specific surface of cement.
v Most important factor that will determines the properties of
cement
v Process of Hydration
• Since hydration starts at the surface of the cement particles it is
the total surface area of cement that represents the material
available for hydration
•The finer the cement is ground, the greater will be its specific
surface.
•So the rate of hydration depends on the fineness of cement
particles & for rapid development of strength higher fineness
necessary.
Dr. Ravi Kant Mittal, BITS, Pilani
b) Fineness
v Fineness cement leads to a stronger reaction with alkali
reaction aggregate & makes a paste though not necessarily
concrete, exhibiting a higher shrinkage & a creates proneness to
cracking.
•However, fine cement bleed less than a coarse one.
•The fineness is the most important factor which determines the
properties of cement:
•Finer grinding increases the speed with which the various
constituents reacts with the water
•Fineness of grinding is of some importance in relation on the
workability of concrete mixes.
•Greater fineness increases the cohesiveness of a concrete mix
•Finer grinding reduces the chances of bleeding of concrete
•In some special type of cement the strength increases slowly than
normal though they are finely grounded.
Dr. Ravi Kant Mittal, BITS, Pilani
RAPID HARDENING PORTLAND
CEMENT
• RAPID hardening Portland cement has similar
properties as that of ordinary Portland cement,
except that the former is more finely ground and
slightly altered in chemical composition.
• Rapid hardening cement gains strength more
rapidly at earlier ages, but has a strength
comparable to that of ordinary Portland cement at
28 days.
• Its fineness leads to increase in shrinkage which
should be accounted for in design.
Dr. Ravi Kant Mittal, BITS, Pilani
PORTLAND SLAG CEMENT(IS455:1989)
• Portland slag cement is manufactured either by
intimately intergrinding a mixture of Portland
cement clinker and granulated slag with addition
of gypsum, or by an intimate and uniform
blending of Portland cement and finely ground
granulated slag.
• The resultant product has physical properties
similar to those of ordinary Portland cement.
• To qualify for a cement as PSC slag content
should be any where from 35 to 70 %
Dr. Ravi Kant Mittal, BITS, Pilani
IRC:15-2011
• Portland sag cement is recommended for
use near where marine environment is
likely to be encountered or where chances
of corrosion exist. For slag cement
maximum limit of granulated blast furnace
slag constituent recommended is 50%
against the IS 456 recommendation for
maximum 70% of the Portland slag cement,
on strength consideration as above.
Dr. Ravi Kant Mittal, BITS, Pilani
PORTLAND SLAG CEMENT…
• In addition, it has low heat of hydration and
with favourable slag contents has relatively
better resistance to soils and water
containing excessive amounts of sulphate,
as well as to acid waters and can, therefore,
be used for marine works with advantage.
• Resistance to sulphates attack
Dr. Ravi Kant Mittal, BITS, Pilani
PORTLAND POZZOLANA CEMENT
IS 1489 (Part 1) : 1991PORTLAND-POZZOLANA
CEMENT- SPECIFICATION PART 1 FLY ASH BASED
• Pozzolana used in the manufacture of Portland
pozzolana cement may be either a natural material
such as diatomaceous earth or materials processed
by calcination of soil (for example, burnt clay
pozzolana) or artificial material such as fly ash.
• Portland pozzolana cement can be produced either
by grinding together Portland cement clinker and
pozzolana in proportions of 15 to 35 percent with
the addition of gypsum, or by intimately and
uniformly blending ordinary Portland cement and
fine pozzolana.
Dr. Ravi Kant Mittal, BITS, Pilani
•When mixed with ordinary Portland cement the silica of the
puzzolana combines with the free lime released during the hydration
of cement. This action is called puzzolanic action.
•The silica in the puzzolana reacts with the lime produced during
hydration of Portland cement and contributes to development of
strength.
•Slowly and gradually additional calcium silicate hydrate is formed
which is a binder and fills up the space, gives impermeability,
durability and ever increasing strength.
Dr. Ravi Kant Mittal, BITS, Pilani
PORTLAND POZZOLANA CEMENT…..
• This cement produces less heat of hydration and
offers greater resistance to the attack of aggressive
waters than ordinary Portland cement.
• It is particularly useful in marine construction and
other mass concrete structures.
• It can generally be used whenever ordinary
Portland cement is usable under normal
conditions.
Dr. Ravi Kant Mittal, BITS, Pilani
IS 1489 (Part 1) : 1991PORTLAND-POZZOLANA
CEMENT —SPECIFICATION PART 1 FLY ASH
BASED
• Portland-pozzolana cement produces less heat of
hydration and offers greater resistance to the attack
of aggressive waters than normal Portland cement.
• Moreover, it reduces the leaching of calcium
hydroxide liberated during the setting and hydration
of cement.
• It is particularly useful in marine and hydraulic
construction and other mass concrete structures.
• Portland-pozzolana cement can generally be used
wherever 33 grade ordinary Portland cement is
usable under normal conditions.
Dr. Ravi Kant Mittal, BITS, Pilani
IS 1489 (Part 1) : 1991PORTLAND-POZZOLANA
CEMENT —SPECIFICATION PART 1 FLY ASH BASED
• However, it should be appreciated that all
pozzolanas need not necessarily contribute
to strength at early ages.
• In view of this fact, this specification has
been prepared to enable manufacturers to
produce Portland-pozzolana cement
equivalent to 33 grade ordinary Portland
cement on the basis of the 3, 7 and 28-days
compressive strength. (next slide)
Dr. Ravi Kant Mittal, BITS, Pilani
IS 1489 (Part 1) : 1991PORTLAND-POZZOLANA
CEMENT —SPECIFICATION PART 1 FLY ASH BASED
• Compressive strenght of 1cement, 3 sand mortar
• a) At 72 ± 1 h , 16 MPa, Min
• b) At 168 ± 2 h , 22 MPa, Min
• c) At 672 ± 4 h , 33 MPa, Min
For construction of structures using rapid construction
methods like slipform construction, Portland-pozzolana
cement shall be used with caution since 4 to 6 hour strength
of concrete is considered significant in such construction.
Dr. Ravi Kant Mittal, BITS, Pilani
HYDROPHOBIC CEMENT
• HYDROPHOBIC CEMENT- deteriorates very little
during prolonged storage under unfavourable conditions.
• This cement is obtained by intergrinding ordinary Portland
cement clinker with certain hydrophobic agents (such as
oleic acid, stearic acid, naphthenic acid,
pentachlorphenol,etc) which will impart a water
repelling property to the cement. (Hydrophobic cement
should not be confused with water proofing cements.)
• With the use of hydrophobic cements, a longer period for
mixing may be necessary.
Dr. Ravi Kant Mittal, BITS, Pilani
PORTLAND LOW HEAT CEMENT,
• 6.1 Fineness
• When tested for fineness by Blaine’s air
permeability method as described in IS
4031 ( Part 2 ) :1988, the specific surface of
cement shall be not less than 320 m2/kg.
Dr. Ravi Kant Mittal, BITS, Pilani
LOW HEAT CEMENT
• 6.2 Soundness
• 6.2.1 When tested by ‘Le Chatelier’ method
and autoclave test described in IS 4031 (
Part 3 ) : 1988, unaerated cement shall not
have an expansion of more than 10(5 for
aerated) mm and 0.8% (0.6 for aerated),
respectively.
Dr. Ravi Kant Mittal, BITS, Pilani
SULPHATE RESISTING
PORTLAND CEMENT-IS : 12330 - 1988
• Use of sulphate resisting Portland cement is
particularly beneficial in such conditions
where the concrete is exposed to the risk of
deterioration due to sulphate attack, for
example, in contact with soils and ground
waters containing excessive amounts of
sulphates as well as for concrete in sea
water or exposed directly to sea coast.
Dr. Ravi Kant Mittal, BITS, Pilani
Sulphate resisting Portland cement
• Sulphate resisting Portland cement is a type
of Portland cement in which the amount of
tricalcium aluminate is restricted to an
acceptably low value (Max.C3A is 5%).
• This cement should not be mistaken for
supersulphated cement, which is produced
by intergrinding or intimately blending a
mixture of granulated blast furnace slag,
calcium sulphate and a small amount of
Portland cement or Portland cement clinker
or any other source of lime.
Dr. Ravi Kant Mittal, BITS, Pilani
• Sulphate resisting Portland cement can be
used for structural concrete wherever
ordinary Portland cement or Portland
pozzolana cement or Portland slag cement
are useable under normal conditions.
• Use of supersulphated cement is, however,
generally restricted where the prevailing
temperature is below 40ºC. The later is not
recommended for producing steam-cured
products.
Dr. Ravi Kant Mittal, BITS, Pilani
Dr. Ravi Kant Mittal, BITS, Pilani
Dr. Ravi Kant Mittal, BITS, Pilani
Dr. Ravi Kant Mittal, BITS, Pilani
HIGH ALUMINA CEMENT
• High alumina cement is usually used when
durability against extreme sulphate or acid
attack is desirable, and when very early
development of strength is required.
• About 80% strength is developed at age of 24
hrs even at 6 to 8 hrs.
• It has initial set of 4 hrs and final set of about
5hrs
• However, this type of cement undergoes
conversion or a sudden change of volume
under humid and hot environments (> 27°C),
thereby leading to loss of strength and
disintegration.
Dr. Ravi Kant Mittal, BITS, Pilani
• Therefore, in tropical countries, such as
India high alumina cement should be used
with extreme care and caution, both in
workmanship as well as in structural design.
• High alumina cement should always be
used in accordance with the manufacturer’s
recommendations.
• It should not be mixed with either other
hydraulic cements, lime, calcium chloride
or with sea water.
Dr. Ravi Kant Mittal, BITS, Pilani
SUPERSULPHATED
CEMENT-IS 6909 : 1990
• Supersulphated cement (SSC) shall be
manufactured by intergrinding or intimately
blending a mixture of granulated blast furnace
slag, calcium sulphate and a small amount of 33
grade ordinary Portland cement, Portland clinker
or any other source of lime ( see Note ).
• The dry granulated blast furnace slag
component of the mixture shall not be less than
70 percent by mass.
Dr. Ravi Kant Mittal, BITS, Pilani
• When tested by Blaine’s air permeability
method given in IS 4031 (Part 2) : 1988, the
SSC shall have a fineness (specific surface)
of not less than 400 m2/kg;
Dr. Ravi Kant Mittal, BITS, Pilani
Quick Setting Cement:
• Quick setting cement is produced by reducing
the percentage of gypsum and adding a small
amount of aluminium sulphate during the
manufacture of cement.
• Finer grinding also adds to quick setting
property. This cement starts setting within 5
minutes after adding water and becomes hard
mass within 30 minutes.
• This cement is used to lay concrete under
static or slowly running water.
Dr. Ravi Kant Mittal, BITS, Pilani
Dr. Ravi Kant Mittal, BITS, Pilani
• it is amazing to note the versatile nature of Abram's law
as it is applicable even today!
mixing water should not be confused with curing water,
which is applied on concrete surface only, after the initial
setting period of concrete.
The absolute min. quantity of W/c ratio
required for hydration as per literature is 0.25.
But it will make the mix quite stiff. We should use superplastizers, in order to make the mix workable, if we are
adopting such water cement ratio.
• In practice, we adopt a W/c ratio of 0.40-0.5. Less W/c
ratio is often required in high-strength concretes only.
Dr. Ravi Kant Mittal, BITS, Pilani