STUDY ON DURABILITY OF CONCRETE WHEN BLENDED WITH MICRO SILICA AND FLYASH

69
International Journal of Research and Innovation (IJRI)
STUDY ON DURABILITY OF CONCRETE WHEN BLENDED WITH
MICRO SILICA AND FLYASH
R.nandini 1
, K. Mythili2
1 Research Scholar, Department Of Civil Engineering, Aurora's Scientific Technological & Research Academy, Hyderabad, India
2 Associate Professor, Department Of Civil Engineering, Aurora's Scientific Technological & Research Academy,Hyderabad, India
*Corresponding Author:
R.nandini,
Research Scholar, Department of CIVIL Engineering,
Aurora's Scientific Technological & Research Academy,
Hyderabad, India
Published: October 29, 2014
Review Type: peer reviewed
Volume: I, Issue : II
Citation:R.nandini,(2014) Durability Of Concrete When
Blended With Micro Silica And Fly Ash
INTRODUCTION
GENERAL
Concrete is one of the most extensively use con-
struction materials in the world, with about two
billion tons of utilization worldwide each year. It
is attractive in many applications because it offers
considerable strength at a relatively low cost. Con-
crete can generally be produced of locally available
constituents, can be cast in to wide variety of struc-
tural configurations, and requires minimal mainte-
nance during service. However, environmental con-
cerns, stemming from high-energy expense and CO2
emission associated with cement manufacture, have
brought pressures to reduce consumption through
the use of supplementary materials.
In general concrete is said to be a very durable one.
But when reinforced concrete structure subjected
to severe environmental conditions its properties
are affected adversely depending on the type of ex-
posure. Durability is one the most important prop-
erties to be considered in the design of reinforced
concrete structures exposed to aggressive environ-
ments can be described by two stages: the initiation
and the propagation period.
For the exposed to sea water or deicing salts, the
initiation period is defined by the time taken from
initial exposure to the aggressive environment un-
til a concentration of reinforcement able to initiate
corrosion, has been reached. However, even though
corrosion of the reinforcement is in progress the
structure still meet the service requirements for
several years without high maintenance costs. The
largest economic benefits are obtained by prolong-
ing the initiation period through proper concrete
mix selection, smart structural design and proper
on-site placement of the concrete among others.
In both developed and developing countries recent
researchers amide at the energy conservation in the
cement and concrete industry, focused on the use
of less energy intensive materials such as Fly-ash,
slag and natural pozzlolanas. Later some attention
has been given to the use of pozzolana, Micro silica
as partial replacement to Portland cement. Unlike
natural pozzolanas and fly ash, the silica reaction
Abstract
The environment in some concrete structures can become very acidic due to formation of sulphuric acid con-
verted from hydrogen sulphide by bacterial action. Significant deteriation of concrete in such harsh environments has
been reported world wide. Deteriotation of sewer system may result in serious problem such as the loss of ability to
transport sewerage, contamaniation of ground and ground water, excessive ground settelements.
Very high costs are involved with the repair of deteriorated concrete structures. In the USA, sulphuric acid is
responsible for billoins of dollars of damage to concrete waste water collection and treatment systems. In the state of
south Australia alone an estimated budjet for maintaining the existing waste water infra structure is A $ 48 million
per anum. Although it has been reported that some new materials can be more acid resistant such as concretes using
melted sulphur as the binder or high proportions of polymer modified binders, these materials are too expansive for most
practical applications. Therefore, the research into improvement of acid resistance of normal concretes is still attractive.
Over the past 20 years the use supplementary cementitious materials (SCM) in concrete has become very com-
mon due to their technological, economical and environmental benefits. The use of SCM such as Micro silica and fly ash
in concretes has been found to improve the resistance of concrete sulphuric acid attack because of the reduced pres-
ence of calcium hydroxide, which is most vunerable to acid attack. Using Micro silica in binary cement system as partial
replacement of ordinary portland cement was found to be effective in reduciton of acid attack.
In the present investigation, 5% Micro Silica and 15 % Fly Ash is added by the weight of the cement as additional ingre-
dients in concrete with different water/ binder ratios 0.55, 0.45 and 0.35 of Ordinary concrete and Ternary concrete mix
. The behaviour of this Ordinary concrete and Ternary concrete mix studied for durablity properties like % Weight loss,
% Loss of Compressive strength and Durability Factors by the immersion concrete specimens in 5% H2
SO4
and 5 % HCl
solution for 28 days,90 days and 180 days.
1401-1402

70
involving Micro silica is rapid and therefore, a long
curing period is not necessary.
Pozzolonic Materials:
Pozzolonic materials are finely divided siliceous and
aluminous materials and have little or no cementa-
tious value and in the presence of moisture at or-
dinary temperature, chemically react with calcium
hydroxide liberated during hydration, to form com-
pounds possessing cementatious properties. The
engineering benefits likely to be derived from the
use of pozzolonas in concrete include improved re-
sistance to thermal cracking because of lower heat
of hydration, enhancement of ultimate strength and
impermeability due to pore refinement, a better du-
rability to chemical attacks such as acid, sulphate,
water and alkali-aggregate expansion.
Types Of Pozzolonas:
Pozzolonic materials can be divided in to two Types
1.Natural pozzolonas
2.Artificial pozzolonas.

Natural pozzolonas such as clay and shale, diato-
maceous earth etc are processed involving crush-
ing, grinding and size preparation, including ther-
mal activation if necessary. The natural pozzolonas
have lost their popularity in view of the availability
of more active pozzolonas available as industrial by
products.
Artificial pozzolonas such as fly ash, blast furnace
slag, micro silica, rice husk ash, metakaoline are
major industrial by products.
Advantages of Pozzolonas:
Generally concrete fails due to combined action of
various detrimental agencies. Durability of concrete
depends on many factors including volume change
of concrete. Physical effects that adversely influ-
ence the durability of concrete include surface wear,
cracking due to crystallization, pressure of salts in
pores and exposure to extreme temperatures, del-
eterious chemical effects including leaching of the
cement paste by acidic solutions and expansive re-
actions involving alkali-aggregate attack, sulphate
attack and corrosion of embedded steel in concrete.
The aspect of progressive hydration of cement is
connected with the volume change of gel and conse-
quently in interior space. The unsoundness of con-
stituent materials such as cement, reactive aggre-
gates containing unsound mineral fractions causes
volume changes and hence affects durability.
Fly Ash:
Fly ash is divided into three classes depending on
its calcium content, in recognition of the difference
in behavior between low and high lime fly ashes.
These classes are as follows:
Type F, low calcium, 8% CaO
Type CI, intermediate calcium, 8–20% CaO
Type CH, high calcium, .20% CaO
Advantage of fly Ash in concrete:
The technical benefits of using fly ash in concrete
are numerous. The various advantages found by dif-
ferent investigators in India are summarized bellow
1. Superior pozzalonic action
2. Reduced water demand (for fly ash low carbon
content and high fineness)
3. Improved workability
4. More effective action of water reducing admix-
tures
5. Reduced segregation and bleeding
6. increases setting time but remains within limits
7. Less heat of hydration
8. Less drying shrinkage
9. Higher ultimate compressive strength, tensile,
flexural and bond strength
11. Higher ultimate modulus of elasticity.
12. Reduced alkali-aggregate reaction
13. Improved freezing and thawing
Micro Silica:
During the last three decades, some new Pozzolan
materials have emerged in the building industry as
an off shoot of research aimed at energy conser-
vation and strict enforcement of pollution control
measures to stop dispersing the materials into the
atmosphere. Micro Silica (other names have been
used are silica dust, condensed silica fume) is one
such Pozzolan, which has been used as a partial
replacement of Portland cement due to its versatile
properties. The availability of high range water-re-
ducing admixtures (superplasticizers) has opened
up new ideas for the use of Micro Silica as part of
the cementing material in concrete to produce very
high strength cement (> 100 Mpa/15,000 psi).
Ternary Blended System (Ternary cement sys-
tem):
It means Micro Silica or other cement replacement
additives are to be used with OPC only. That is not
strictly true and ternary mixtures comprise efficient
-systems. The primary incentive of adding limited
amount Micro Silica –for example 5 percent with
Fly-ash cement mixes was to ensure high early
strength research has however, shown that Ternary
mixtures of OPC, Micro Silica and Fly-ash result in
synergic action to improve the micro structure and
performance of concrete. When both Micro Silica
and Fly-ash are used, the resultant enhancement
of strength or pozzolanic activity was greater than
super position of contributions of each, for the re-
spective proportions. Such synergic effect results
from strengthening the weak transition zone in ag-
gregate cement interface, as well as segmentation
and blocking of pores.
Depending upon the service environment in which

71
it is to operate, the concrete structure may have
to encounter different load and exposure regimes.
In order to satisfy the performance requirements,
different ternary compounds required. Such as ce-
ment, fly-ash, silica fume. Greater varieties are in-
troduced by the corporation of additives like poz-
zolana, granulated slag are inert fillers this leads
to different specifications of cements in national or
international.
Effects of Ternary cement system:
The combination of Micro Silica and Fly ash in a
Ternary cement system (i.e., portland cement being
the third component) should result in a number of
synergistic effects, some of which are obvious or in-
tuitive, as follows:
• Micro Silica compensates for low early
strength of concrete with low CaO fly ash.
• Fly ash increases long-term strength devel-
opment of Micro Silica concrete.
• Fly ash offsets increased water demand of
silica fume.
• Micro Silica reduces the normally high levels
of high CaO fly ash required for sulphate resist-
ance and ASR prevention.
• Very high resistance to chloride ion penetra-
tion can be obtained with ternary blends.
• Fly ash due to presence of spherical particles
that easily rollovers one another reducing inter par-
tial friction (call bearing effects) leads to improved
workability and reduction in water demand.
Durability advantage:
Since industrial wastes are relatively lesser-known
materials than cement, it possible to have ques-
tions on their long-term effects on concrete. Doubts
about effects of Fly ash and Micro Silica on durabil-
ity of concrete had initially inhibited their full use
in structural concrete. However, experience over
the years and continuous research has actually re-
vealed positive effects on durability. Corrosion of re-
inforcement, sulphate attack, heat of hydration and
alkali silica reaction (ASR) in concrete are the ma-
jor issues of durability. Use of Fly ash, Micro Silica
is known to be beneficial in all such cases. These
are supported by well-documented case studies and
performance records reported from foreign sources.
Data and case studies on Indian experiences with
indigenous materials have been presented earlier,
hence only the salient trends are enumerated.
Aim of the Present Study:
The environment in some concrete structures can
become very acidic due to formation of sulphuric
acid converted from hydrogen sulphide by bacterial
action. Significant deteriation of concrete in such
harsh environments has been reported world wide.
Deteriotation of sewer system may result in serious
problem such as the loss of ability to transport sew-
erage, contamaniation of ground and ground water,
excessive ground settelements.
Very high costs are involved with the repair of dete-
riorated concrete structures. In the USA, sulphuric
acid is responsible for billoins of dollars of damage
to concrete waste water collection and treatment
systems. In the state of south Australia alone an
estimated budjet for maintaining the existing waste
water infra structure is A $ 48 million per anum.
Although it has been reported that some new mate-
rials can be more acid resistant such as concretes
using melted sulphur as the binder or high propor-
tions of polymer modified binders, these materials
are too expansive for most practical applications.
Therefore, the research into improvement of acid re-
sistance of normal concretes is still attractive.
Over the past 20 years the use supplementary ce-
mentitious materials (SCM) in concrete has become
very common due to their technological, economical
and environmental benefits. The use of SCM such
as Micro silica and fly ash in concretes has been
found to improve the resistance of concrete sulphu-
ric acid attack because of the reduced presence of
calcium hydroxide, which is most vunerable to acid
attack. Using Micro silica in binary cement system
as partial replacement of ordinary portland cement
was found to be effective in reduciton of acid attack.
In the present investigation, 5% Micro Silica and 15
% Fly Ash is added by the weight of the cement as
additional ingredients in concrete with different wa-
ter/ binder ratios 0.55, 0.45 and 0.35 of Ordinary
concrete and Ternary concrete mix . The behaviour
of this Ordinary concrete and Ternary concrete mix
studied for durablity properties like % Weight loss,
% Loss of Compressive strength and Durability Fac-
tors by the immersion concrete specimens in 5%
H2SO4 and 5 % HCl solution for 28 days,90 days
and 180 days.
EXPERMENTAL INVESTIGATION
Introduction:
The present investigations are aimed at to study
durability of Ternary Blended concrete, having 5%
Silica fume and 15% Fly Ash by weight of cement
with different W/B ratios 0.55, 0.45and 0.35. In the
laboratory after the age of 28 Days, 90 Days and
180 Days.
MATERIALS
Cement
Locally available 53 grade of Ordinary Portland Ce-
ment (Ultra Tech Brand.) confirming to IS: 12269
was used in the investigations. Table 4.1 gives the
physical properties of OPC used in the present in-
vestigation and they conform to IS specifications.

72
Photomicrograph of Portland cement (Curtsy
Micro Silica Manual)
Fly Ash:
The fly ash obtained from Hyderabad Industries,
Andhra Pradesh is used in the present experimental
work.
Table 4.4.1 gives properties of flyash. The chemical
composition of flyash is rich in silica content which
react with calcium hydroxide to form C-S-H gel.
This gel is responsible for the strength mortar or
concrete. The fly ash used to the specification of
grade 1 flyash
Photomicrograph of Fly ash (Curtsy Aci Jurnal)
Micro Silica:
The Micro Silica obtained from ‘ Oriental Trexim Pvt
Ltd ‘. Micro Silica conforming to a standard approved
by the deciding authority may be used as part
replacement of cement provided uniform blending
with the cement is ensured. The Micro Silica (very
fine non-crystalline silicon dioxide) is a by-product
of the manufacture of silicon, ferrosilicon or the
like, from quartz and carbon in electric arc furnace.
Table 4.5.1 gives properties of Micro Silica. The
chemical composition of Micro Silica is rich in silica.
Micrograph showing: Micro Silica (Curtsy by
Micro Silica Manual)
AGGREGATE:
The size, shape and gradation of the aggregate play
an important role in achieving a proper concrete. The
flaky and elongated particles will lead to blocking
problems in confined zones. The sizes of aggregates
will depend upon the size of rebar spacing.
The coarse aggregate chosen for Ternary Blended
Concrete is typically angular in shape, is well
graded, and smaller in maximum size that suited
for conventional concrete; typical conventional
concrete should have a maximum aggregate size of
20mm. Gradation is an important factor in choosing
a coarse aggregate, especially in typical uses of
Ternary Blended. Gap-graded coarse aggregate
promotes segregation to a greater degree than the
well graded coarse aggregate.
Fine Aggregates:
The locally available sand is used as fine aggregate
in the present investigation. The sand is free from
clayey matter, salt and organic impurities. The sand
is tested for various properties like specific gravity,
bulk density etc., and in accordance with IS 2386-
1963. The fine aggregate is conforming to standard
specifications.
Coarse Aggregates:
Machine crushed angular granite metal of 20mm
nominal size from the local source is used as coarse
aggregate. It is free from impurities such as dust,
clay particles and organic matter etc. The course
aggregate is also tested for its various properties.
The specific gravity, bulk density and fineness
modules of coarse aggregate are found to be 2.70,
1560 kg/cum and 7.1 respectively.
Water:
Locally available water used for mixing and curing
which is potable, shall be clean and free from
injurious amounts of oils, acids, alkalis, salts,
sugar, organic materials or other substances that
may be deleterious to concrete or steel.

73
Superplasticizer:
Superplasticizer CONPLAST 430 of Fosroc Chemical
India Ltd. Was used as water reducing admixture. It
increases workability
Mix Proportion in the Laboratory:
The proportion used in preparation of mix is
calculated as per BIS Method.
The ratio between F.A and C.A is p: (1-p )
Illustrative Example for Mix Design
Mix Design for W/C ratio = 0.55
i. Text data for materials
Specific gravity of cement =2.95
Specific gravity of Coarse Aggregate =2.70
Specific gravity of Fine Aggregate =2.53
ii. Selecting W/B ratio =0.55
iii. Determination of cement content
Water =178 Ltrs.
Cement =323.6 Kgs.
iv. Determination of F.A and C.A
Fine Aggregate
0.98= [178+ (323.6/2.95)+
(1/0.42)*(F.A/2.53)]*1/100=736 Kgs.
Coarse Aggregate
0.98= [178+ (323.6/2.95)+ (1/1-0.42)*(C.A/1-
2.2.7)]*1/100= 1084 Kgs.
v. Mix Proportion = 1.00:2.27:3.34:0.55
Similarly Mix proportions for other W/B are obtained
and are as follows;
For W/B ratio 0.55 Ternary Blended Concrete mix
proportion is 1.00:2.27:3.34:0.55
For W/C ratio 0.45 Ordinary Concrete mix
proportion is 1.00:1.78:2.73:0.45
proportion is 1.00:1.78:2.73:0.45
For W/C ratio 0.35 Ordinary Concrete mix
proportion is 1.00:1.26:2.11:3.55
proportion is 1.00:1.26:2.11:3.55
PREPARATION OF TEST SPECIMENS:
Mixing:
Mixing of ingredients is done in a rotating drum.
Thorough mixing by hand, using trowels is adopted.
The cementitious materials are thoroughly blended
with hand and then the aggregate is added and mixed
followed by gradual addition of water and mixing.
Wet mixing is done until a mixture of uniform color
and consistency are achieved which is then ready for
casting. Before casting the specimens, workability
of the mixes was found by compaction factor test.
The concrete mix design using the data obtained from
the test on its ingredients. The mix proportions with
different W/B ratios are shown in the table 4.6.1,
4.6.2 and 4.6.3 of Ordinary concrete and Ternary
Blended Concrete. The adopted is BIS method.
Workability Test:
Immediately after mixing each of concrete, was tested
for workability by compaction factor apparatus
in the laboratory. Table 4.7 gives the Compaction
Factor value for different mixes, and the Degree of
Workability of mixes is medium for W/B 0.55, 0.45
and 0.35 of Ordinary and Ternary Blended Concrete
Compaction:
All the specimens were compacted by using pin
vibrator.
Casting of Specimens:
The cast iron moulds are cleaned of dust particles
and applied with mineral oil on all sides before
concrete is poured in the moulds.
The moulds are of size 100mm x 100mm for cubes
.The moulds are placed on a level platform. The well
mixed green concrete is filled in to the moulds by
vibration with needle vibrator. Excess concrete was
removed with trowel and top surface is finished level
and smooth.
Curing of the Specimens:
The specimens are left in the moulds undisturbed at
room temperature for about 24 hours after casting.
The specimens are then removed from the moulds
and immediately transferred to the curing pond
containing clean and fresh water.
Testing of Specimens:
A time schedule for testing of specimens is
maintained to ensure their proper testing on the

74
due date and time. The cast specimens are tested as
per standard procedures, immediately after they are
removed from curing pond and wiped off the surface
water. The test results are tabulated carefully
Description of Compression Testing Machine:
The compression testing machine (Microprocessor
based) used for testing the cube specimens is of
standard make. The capacity of the testing machine
is 200 Tonnes or 2000 KN. The machine has an
ideal gauge on which the load applied can be read
directly. The oil level is checked, the MS plates are
cleaned and the machine is kept ready for testing
specimens.
Testing Arrangements:
The specimens are removed from the curing
pond just before testing on the specified due date
and time and cleaned to wipe off the surface water.
The cube specimen is placed on the lower platen
such that the load is applied centrally on the faces
other than top and bottom faces of casting.
TESTS CONDUCTED:
Compressive strength of Concrete Specimens:
The compressive strength of control concrete
(ordinary concrete) and Ternary Blended concrete
contain 5% Micro Silica and 15% Fly ash concrete
specimens having W/B 0.55, W/B 0.45 and W/B
0.35 were tested.
Durability Studies of Ordinary and Ternary
Blended Concrete:
In addition to strength durability property is also
important for concrete, when concrete is exposed to
aggressive environment consisting of chlorides and
sulphates it should not be subjected to deterioration.
Pozzolanic admixtures are replacements for cement
in concrete are known to enhance the durability
property of the concrete. To study the effect of Fly
ash and Micro Silica replacement on durability,
acid resistance test have been conducted in the
laboratory.
DURABILITY OF CONCRETE:
The durability of Control concrete and Ternary
blended concrete was tested for resistance against
mineral and organic acids such as Sulphuric acid,
hydrochloric acid and chlorides etc. The effect
of chemical attack on plain (ordinary concrete)
concrete and Ternary concretes was studied by
physical observation and loss in weight.
Acid pond test:
Acid solution for immersion test. The method was
modified for testing concrete in this investigation.
A H2
SO4
(Sulphuric) acid and HCl (Hydro chloride
Acid) of 5% concentration was chosen for this
accelerated laboratory investigation to simulate the
aggressive environment of some sewer structures.
All the concrete cubes of 100mmx100mm size were
continuously immersed in weekly refreshed 5%
H2SO4 and HCl acid during the test period.
Visual inspection of concrete samples:
During the immersion period in 5% H2
SO4
(Sulphuric)
acid and HCl (Hydro chloride Acid) solution, the
concrete cube samples were periodically retrieved
from the acid solution for visual inspection of the
surface appearance. Photographs were also taken
of cubes samples after immersion in the acid over
different time periods to record changes in surface
appearance.
Mass changes of cubes over immersion time:
The mass change of the cubes of each concrete with
the immersion time in 5% H2
SO4
(Sulphuric) acid
and HCl (Hydro Chloride Acid) solution.
EXPERIMENTAL RESULTS
Cement:
Physical Properties of Ordinary Portland Cement
S.No. Property Test Results
1 Normal Consistency 32%
2 Initial Setting time 90 min
3 Final Setting time 250 min
4 Specific Gravity of Ce-
ment
2.95
5 Compressive Strength
(at 28 days)
56.3 N/mm2
Fine Aggregate:
Physical Properties:
S.No Property Test Results
1 Fineness
modulus
2.48
2 Specific gravity 2.53
3 Bulk density
a).Loose
b). Com-
pacted
1600 kg/m3
1720 kg/m3

75
Sieve analysis: Sample 1000 gms
S.No. I.S
Sieve
Size
Wt.
Retained
(gms.)
Cumu-
lative
Wt. Re-
tained
(gms.)
Cumula-
tive %
of wt
Retained
% Pass-
ing
1 4.75
mm
0.61 0.61 0.061 99.939
2 2.36
mm
2.6 3.21 0.321 99.679
3 1.18
mm
40 43.21 4.32 95.68
4 600µ 463 506.21 50.62 49.38
5 300µ 432 938.21 93.82 6.18
6 150µ 59.8 998.01 99.8 0.2
7 <150µ 2 1000 100 0
Total 1000 -- 248.94 --
Fineness modulus = 248.94/100 = 2.48
Coarse Aggregate:
Physical Properties
S.No Property Test Results
1 Fineness modulus 7.17
2 Specific gravity 2.70
3 Bulk density
a).Loose
b). Dense
1390 kg/m3
1560 kg/m3
4 Flakiness index 2.41%
5 Elongation index 12.80%
Sieve analysis of 20mm aggregate: Sample 5000
gms
S.No IS
Sieves
size
Wt. Re-
tained
(gms.)
Cumula-
tive wt.
Retained
(gms)
Cumula-
tive % of
wt. Re-
tained
% Passing
1 40 mm 0 0 0 100
2 20 mm 915 915 18.30 100
3 10 mm 3994 4909 99.09 81.70
4 4.75mm 45 4954 100 0.92
5 2.36
mm
0 5000 100 0
6 1.18
mm
0 5000 100 0
7 600 µ 0 5000 100 0
8 300 µ 0 5000 100 0
9 150 µ 0 5000 100 0
Total 5000 717.38
Fineness modulus of Coarse aggregate =
717.8/100 = 7.17
Mix Design:
Percentages Mineral Ingredients of Ordinary
Concrete and Ternary Blended Concrete Mixes:
Mix Type W/C % of Ce-
ment
% of Micro
Silica
% of Fly ash
Ordinary
Concrete
Mixes
0.55 100 - -
0.45 100 - -
0.35 100 - -
Ternary
Blended
Concrete
Mixes
(5%Micro
Silica-15%
Fly ash)
0.55 80 5 15
0.45 80 5 15
0.35 80 5 15
W/B
Type of Con-
crete
5% H2SO¬4 Solution 5% HCl Solution
Sr N M D.F Sr N M D.F
0.55 Ordi-
nary
Con-
crete
65.80
28 180 10.23 90.62 28 180 14.03
45.37
90 180 22.68 80.40 90 180 40.20
31.70
180 180 31.70 74.89 180 180 74.89
Ter-
nary
Blend-
ed
Con-
crete
68.01
28 180 10.57 91.61 28 180 14.25
47.84
90 180 23.92 85.99 90 180 42.99
33.08
180 180 33.08 77.39 180 180 77.39
0.45 Ordi-
nary
Con-
crete
71.89
28 180 11.18 92.44 28 180 14.37
51.08
90 180 25.54 87.58 90 180 43.79
36.06
180 180 36.06 80.09 180 180 80.09
Ter-
nary
Blend-
ed
Con-
crete
74.35
28 180 11.56 93.58 28 180 14.55
53.34
90 180 26.67 88.10 90 180 44.05
41.41
180 180 41.41 81.75 180 180 81.75
0.35 Ordi-
nary
Con-
crete
75.89
28 180 11.80 94.66 28 180 14.72
56.80
90 180 28.40 89.50 90 180 44.75
43.92
180 180 43.92 83.77 180 180 83.77
Ter-
nary
Blend-
ed
Con-
crete
77.80
28 180 12.10 95.49 28 180 14.85
59.45
90 180 29.72 91.45 90 180 45.72
46.67
180 180 46.67 84.84 180 180 84.84
Sr=Relative strength at N days (%),
N=Number of days at which the durability factor is
needed,
M= Number of days at which exposure is to be ter-
minated,
D.F= Durability Factor.

76
GRAPHS
Percentage of weight loss vs. Age in Days for W/B
0.55 Immersed in 5%H2SO4 Solution at 28 days,
90 days and 180 days.
0.45 Immersed in 5%H2SO4 Solution at 28 days, 90
days and 180 days.
0.35 Immersed in 5%H2SO4 Solution at 28 days, 90
days and 180 days.
0.55 Immersed in 5%HCl Solution at 28 days, 90
days and 180 days.
days and 180 days.
Percent age of weight loss vs. Age in Days for W/B
days and 180 days.

77
Combined Graph Percentage of weight loss vs. Age
in Days for W/B 0.55, 0.45 and 0.35 Immersed in
5% H2
SO4
Solution at 28 days, 90 days and 180
days.
Combined Graph Percentage of weight loss vs. Age
in Days for W/B 0.55, 0.45 and 0.35 Immersed in
5%HCl Solution at 28 days, 90 days and 180 days.
Percentage Loss of Compressive strength of after
immersed in 5% H2
SO4
Solution at 28 days, 90 days
and 180 days.
Percentage Loss of Compressive strength of after
immersed in 5% HCl Solution at 28 days, 90 days
and 180 days.
DISCUSSION OF TEST RESULTS
Durability Studies on Ternary Blended Concrete
In addition to the strength, durability properties
are also important for concrete. When concrete
is exposed to aggressive environment consisting
of sulphate, acids, chlorides. It should not be
subjected to deterioration. Pozzolonic admixtures
as replacement for cement in concrete are known
to enhance the durability property of concrete.
To study the test of Ternary Blended Concrete on
durability acid resistance test and Rapid Chloride
Permeability Test have been conducted in the
laboratory.
Concrete specimens of size 100X100X100 mm are
cured for 28 days and are immersed in 5% HCL , 5%
H2
SO4
for the period of 28 days , 90 days and 180
days of different water binder ratios of 0.55 , 0.45,
and 0.35. All types of experiments are conducted
for comparison of Ordinary Concrete and Ternary
Blended Concrete in respect of acid resistance.
Studies on Loss of weight of Ordinary concrete and
Ternary Blended concrete in different solutions
Loss of weight of specimens after immersing in 5%
H2
SO4
solution
Table 4.8.1 gives the percentage weight loss of W/C
ratios 0.55, 0.45 and 0.35 of ordinary concrete after
immersing in 5% H¬2 SO4 solution ranges from
4.87% to 2.12% for 28 days, 13.17% to 8.95% for 90
days, 17.16 % to 11.29% for 180 days respectively.
Table 4.8.2 gives the percentage weight loss of
W/B ratios 0.55, 0.45 and 0.35 of Ternary Blended
Concrete after immersing in 5% H¬2 SO4 solution
ranges from 3.43 to 1.84% for 28 days, 11.71 to
6.50for 90 days, 15.21% to 9.54% for 180 days
respectively.
The percentage weight loss of W/B ratio 0.55, 0.45
and 0.35 of ordinary concrete and Ternary Blended
Concrete after immersing in 5% H¬2 SO4 solution
increases corresponding to the time.
Loss of Weight of specimens after immersing in 5%
HCl solution
Table 4.9.1 gives the percentage weight loss of W/C
ratios 0.55, 0.45 and 0.35 of ordinary concrete after
immersing in 5% H¬Cl solution ranges from 3.52%
to 1.33% for 28 days, 9.46% to 5.13% for 90 days,
and 12.41% to 7.8 for 180 days respectively.
Table 4.9.2 gives the percentage weight loss of
W/B ratios 0.55, 0.45 and 0.35 of Ternary Blended
Concrete after immersing in 5% H¬Cl solution
ranges from 2.87% to 1.10% for 28 days, 7.38% to
2.79% for 90 days, 10.21% to 4.64% for 180 days
respectively.

78
The percentage weight loss of W/B ratio 0.55, 0.45
and 0.35 of ordinary concrete and ternary concrete
after immersing in 5% Hcl solution increases
corresponding to the time.
Studies on Loss of Compressive strength of
Ordinary and Ternary Blended Concrete
Loss of Compressive strength of specimens after
immersing in 5% H¬2
SO4
solution
Table 4.11.1 gives the percentage Loss of
Compressive strength of W/C ratios 0.55, 0.45 and
0.35 of ordinary concrete after immersing in 5% H¬2
SO4
solution ranges from 34.20% to 24.11% for 28
days, 54.63% to 43.20% for 90 days, and 68.83 %
to 56.92% for 180 days respectively.
Table 4.11.1 gives the percentage Loss of compressive
strength of W/B ratios 0.55, 0.45 and 0.35 of
Ternary Blended Concrete after immersing in 5%
H¬2
SO4
solution ranges from 31.99% to 22.20% for
28 days, 5.63% to 40.55% for 90 days, 66.92% to
58.33% for 180 days respectively.
The Loss of compressive strength of W/B ratio 0.55,
0.45 and 0.35 of ordinary concrete and Ternary
Blended Concrete after immersing in 5% H¬2
SO4
solution increases corresponding to the time.
Under Sulfuric acid attack, calcium sulphate formed,
can continue to react with calcium aluminate phase
in cement to form Calcium Sulphoaluminate,
which on crystallization can cause expansion and
disruption of conctete.
Loss of Compressive strength of specimens after
immersing in 5% HCl solution
Compressive strength of W/C ratios 0.55, 0.45 and
0.35 of ordinary concrete after immersing in 5% HCl
solution ranges from 9.37% to 5.34% for 28 days,
19.60% to 10.50% for 90 days, 25.11% to 16.23%
for 180 days respectively.
Compressive strength of W/B ratios 0.55, 0.45 and
0.35 of Ternary Blended Concrete after immersing
in 5% HCl solution ranges from 8.37% to 4.51% for
28 days, 14.01% to 8.55% for 90 days, 22.61% to
15.16% for 180 days respectively.
The percentage Loss of Compressive strength of
W/B ratio 0.55, 0.45 and 0.35 of ordinary concrete
and Ternary Blended Concrete after immersing in
5% HCl solution increases corresponding to the
time.
Studies on Durability Factors of Ordinary and
Ternary Blended concrete
Durability Factors of Ordinary and Ternary
Blended concrete specimens after immersing in
5% H¬2
SO4
solution
Table 4.12 gives Durability Factors of W/C ratios
0.55, 0.45 and 0.35 of ordinary concrete after
immersing in 5% H¬2 SO4 solution. These values
are observed to be ranges from 10.23 to 11.80 for 28
days, 22.68 to 28.4 for 90 days, and 31.70 to 43.92
Table 4.12 gives the percentage Loss of Compressive
strength of W/B ratios 0.55, 0.45 and 0.35 of
Ternary Blended Concrete after immersing in 5%
H¬2 SO4 solution. These values are observed to
be ranges from 10.57 to 12.10 for 28 days, 23.92
to 29.72 for 90 days, 33.08 to 46.67 for 180 days
respectively.
Durability Factors of Ordinary and Ternary
Blended concrete specimens after immersing in
5% HCl solution
Table 4.12 gives Durability Factors of W/C ratios
0.55, 0.45 and 0.35 of ordinary concrete after
immersing in 5% H¬Cl solution. These values are
observed to be ranges from 14.03 to 14.72 for 28
days, 40.20 to 44.75 for 90 days, and 74.89 to 83.77
Table 4.12 gives the percentage Loss of Compressive
strength of various W/B ratios 0.55, 0.45 and 0.35
of Ternary Blended Concrete after immersing in
5% H¬Cl solution. These values are observed to
be ranges from 14.25 to 14.85 for 28 days, 42.99
to 45.72 for 90 days, 77.39 to 84.84 for 180 days
respectively.
CONCLUSIONS:
The Following Conclusions are drawn from the
Experimental Investigation in present Thesis:
1. From the visual observation of test specimens
immersed in 5% H2SO4 solution for 28 days, 90
days and 180 days, the specimens has undergone
deterioration. Which are viewed in photograph
enclosed.
2. The investigation shows that percentage
of weight loss of specimens increased as days of
immersion in 5% H2SO4 is increased for Ordinary
concrete and Ternary concrete for all W/C ratios. In
case of Ordinary concrete for 0.55 Water/ Cement
ratio the percentage of weight loss is 4.87 at 28 days
immersion and it is 17.16 for 180 days immersion.
In case of Ternary Blended concrete for 0.55 Water/
Binder ratio the percentage of weight loss is 3.43
at 28 days immersion and it is 15.21 for 180 days
immersion.
3. From the visual observation of test specimens
immersed in 5% HCl solution for 28 days, 90 days
and 180 days, the specimens has undergone
deterioration.

79
4. The investigation shows that percentage
of weight loss of specimens increased as days of
immersion in 5% HCl is increased for Ordinary
concrete and Ternary Blended concrete for all W/B
ratios. In case of Ordinary concrete for 0.55 Water/
Cement ratio the percentage of weight loss is 3.52
at 28 days immersion and it is 12.41 for 180 days
immersion. In case of Ternary concrete for 0.55
Water/ Binder ratio the percentage of weight loss is
2.82 at 28 days immersion and it is 10.21 for 180
days immersion.
5. The percentage weight loss of Ordinary
concrete and Ternary Blended concrete after
immersing in 5 % H2SO4 solution increases
6. The percentage weight loss of Ordinary
concrete and Ternary Blended concrete after
immersing in 5 % HCl solution increases
7. The percentage loss compressive strength
of Ordinary concrete and Ternary Blended concrete
after immersing in 5 % H2SO4 solution and 5% HCl
solution increases corresponding to the time.
8. The Durability Factors of Ternary Blended
concrete mixes are more than those of Ordinary
concrete mixes.
9. Higher the Durability Factor higher will be
the resistance to the Acids and Sulphates attacks.
10. A reduction in pores in concrete improves
the surface integrity of concrete, improves its
homogeneity good bonding and reduces the
probability of cracks.
PHOTOGRAPHS:
Ordinary Concrete Specimen of W/C Ratio 0.55
after Immersion in 5% H2
SO4
Solution at 28 days
Ternary Blended concrete Specimen of W/B Ratio
0.55 after Immersion in 5% H2
SO4
Solution at 28
days
SO4
Solution at 90 days.
Ternary Blended Concrete Specimen of W/B Ratio
SO4
Solution at 90
days

80
SO4
Solution at 180 days
SO4
Solution at 180
days
Ordinary Concrete Specimen of W/C Ratio 0.45after
Immersion in 5% H2
SO4
Solution at 28 days
SO4
Solution at 28
days
Ordinary Concrete Specimen of W/C Ratio 0.45after
Immersion in 5% H2
SO4
Solution at 90 days
SO4
Solution at 90
days

81
SO4
SO4
Solution at 180
days
Ordinary Concrete Specimen W/C Ratio 0.35 after
Immersion in 5% H2
SO4
Solution at 28 days
SO4
Solution at 28
days
SO4
Solution at 90 days
SO4
Solution at 90
days

82
SO4
SO4
Solution at 180
days
after Immersion in 5% HCl Solution
0.55 after Immersion in 5% HCl Solution
Ternary Blended Concrete Specimen of W/B
Ratio 0.45 after Immersion in 5% HCl Solution

83
0.35 after Immersion in 5% HCl Solution
References:
1. M.D.A. Thomass, M.H. Shehata, S.G.
Shaishiprakash, D.S.Hopkins, K.Cail. “Use of Ter-
nary cementitious system containing Silica fume
and Fly ash in Concrete”. Cement and concrete Re-
search 29(1999) Pg 1207-1214.
2. Tahir Kemal Erdem, Onder Klrca. “ Use of Binary
and Ternary Blended in high strength concrete’.
Construction and Building materials 22(2008) Pg
1477-1483.
3.M.G.Alexander, B.J.Magee. “Durability perfor-
mance of concrete containing condensed Silica
fume”. Cement and concrete Research29 (1999) Pg
917-922.
4.Roland Bleszynski, R. Doug Hooton, Michael D.A
Thomas, and Chris A. Rogers “ Durabilty of Ter-
nary Blended concrete with Silica Fume and Blast-
Furnace Slag: Laboratory and Outdoor Exposure
Site Studies”. ACI materials journals September-
October 2002.
5. ShwetaGoyal, Maneek Kumar and
B.Bhattacharjee. “ Potential Benefits of incorporat-
ing fly ash in Silica fume concrete”. The INDIAN
Concrete Journal, August 2008.
6. S.P. Pandey, A.K.Singh, R.L.Sharma, A.K.Tiwari.
“ Studies on high-performance blended/ multi-
blended cements and their Durability characteris-
tics “.Cement and concrete Research 33(2003) Pg
1433-1436.
7. Mrdhat H. Shehata, Michael D.A. Thomas. “ Use
of Ternary blends Containing Silica fume and Fly
ash to Suppress expansion due to alkali-silica re-
action in concrete “.Cement and concrete Research
32 (2002) Pg 341-349.
8.A.K. Mullick. “Performance of Concrete with Bi-
nary and Ternary cement blends”. The INDIAN
Concrete Journal, January 2007.
9. Jelica Zelic, Ivana Radovanovic, Drazan Jozic.
“The Effect of silica Fume additions on the Dura-
bility of Portland Cement Mortars Exposed to Mag-
nesium Sulphate Attack”. Materials and Technology
41 (2007), Pg 91-94.
10. P. Maruthi and V. Sivakumar, “Studies on Acid
Resistance of Ternary Blended Concrete “ASIAN
Journal of Civil Engineering (Building and Housing)
Vol.9, No.5 (2008).
11. P.Srinivasa Rao, Seshadri .T and P. Sravana.
“Durability Studies on glass Fibre SCC “The INDIAN
Concrete Journal, October 2009.
12. K.D. Stanish, R.D.Hooton and M.D.A. Thomas. “
Testing the Chloride penetration Resistance of Con-
crete: A Literature Review”. Cement and concrete
Research (1999).
13.A.Elahi, P.A.M.Basheer, S.V. Nanukuttan,
Q.U.Z.Khan.” Mechanical and Durability proper-
ties of high performance concrete containing Sup-
plementary cementitious materials”.Construction of
Building materials 24(2010) Pg 292-299.
14.M.G. Alexander, B.J.Magee.” Durability per-
formance of concrete containing condensed silica
fume”.Cement and Concrete Research 29 (1999) Pg
917-922.
15.M.R.Jones, R.K Dhir and B.J. Magee. ” Concrete
contacting Ternary Blended Binders: Resistance to
Chloride ingress and Carbonation”. Cement and
Concrete Research, vol.27, No.6(1997) Pg 825-831.
16.M.I.Khan, C.J. Lynsdale, P.Waldron. “Poros-
ity and Strength of PFA/SF/OPC Ternary blende
paste”. Cement and Concrete Research 30(2000) Pg
1225-1229.

84
17. A.M.Boddy, R.D.Hooton,M.D.A.Thomas.” The
effect of the Silica content of Silica fumes onits abil-
ity to control alkali-silica reaction”. Cement and
Concrete Research 33(2003) Pg1263-1268.
18. S.K.Antiohos, V.G.Papadakis, E.Chaniotakis,
S.Tsimas. ” Improving the Performance of Ternary
Blended Cements by mixing different types of fly
ashes”. Cement and Concrete Research 37(2007) Pg
877-885.
19. D.S.Lane, C.Ozyildirim. “Preventive measure for
alkali-silica reactions”. Cement and Concrete Re-
search 29(1999) Pg 1281-1288.
Author
Ramanujapuram.Nandini
Aurora's Scientific Technological & Research
Academy,Hyderabad,India
K. Mythili,
AssociateProfessor,
Department of Civil Engineering,
Aurora's Scientific Technological & Research Acad-
emy, Hyderabad, India

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