The use of self-compacting concrete (scc) in general building and civil engineering constructions is becoming popular over the years ever since it was invented and guide-lines have been formulated by the efnarc (european federation of national association representing concrete) in 2005. Although in india, we do not have any specific codal provisions for scc similar to normal concrete, considerable research has been done in both development of scc and its applications with various admixtures and fibers to enhance the properties of scc in hardened state. As scc is very sensitive to variations in moisture content and gradation of aggregates, construction sites face difficulties in free flow of scc.

1. 122
International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI)
INFLUENCE OF VISCOSCITY MODIFYING ADMIXTURES ON FRESH AND HARD-
ENED PROPERTIES OF SELF COMPACTING CONCRETE WITH VARYING DOS-
AGE OF FLYASH
Shraddha1
, M.V.Seshagiri rao2
, K. Mythili3
1 Research Scholar, Department Of Civil Engineering, Aurora Scientific Technological and Research Academy, Hyderabad India.
2 Professor, Department Of Civil Engineering, JNTU Hyderabad, Hyderabad, India
3 Associate professor , Department Of Civil Engineering, Aurora Scientific Technological and Research Academy, Hyderabad India.
*Corresponding Author:
Shraddha ,
Research Scholar, Department Of Civil Engineering,
Aurora Scientific Technological and Research Academy,
Hyderabad India.
Published: January 02, 2015
Review Type: peer reviewed
Volume: II, Issue : I
Citation: Shraddha , Research Scholar (2014) "Influence Of
Viscoscity Modifying Admixtures On Fresh And Hardened
Properties Of Self Compacting Concrete With Varying
Dosage Of Flyash"
INTRODUCTION
GENERAL
Present-day self-compacting concrete (scc) can be
classified as an advanced construction material. As
the name suggests, it does not require to be vibrated
to achieve full compaction. This offers many ben-
efits and advantages over conventional concrete.
These include an improved quality of concrete and
reduction of on-site repairs, faster construction
times, lower overall costs, facilitation of introduc-
tion of automation into concrete construction. An
important improvement of health and safety is also
achieved through elimination of handling of vibra-
tors and a substantial reduction of environmental
noise loading on and around a site. The composi-
tion of scc mixes includes substantial proportions
of coarse and fine-grained inorganic materials and
this gives possibilities for utilization of mineral ad-
mixtures, which are currently waste products with
no practical applications.
OBJECTIVES AND SCOPE
GENERAL
Despite its advantages and versatile nature, SCC
has not gained much popularity in India, though
it has been widely promoted in the Middle East for
the last two decades. Awareness of SCC has spread
across the world, prompted by concerns with poor
consolidation and durability in case of convention-
ally vibrated normal concrete.
All the researchers have developed SCC taking the
CA/FA ratio and also considered the limited content
of coarse aggregate and more content of fines. But,
there are very limited investigations reported con-
sidering the size effect of coarse aggregate content
in the development of SCC. Keeping this in view,
the present experimental investigation is taken up
to study the effect of size of coarse aggregate in the
development of M70 grade of Self Compacting Con-
crete. Powder content is the main aspect of a SCC
mix design. In the present work, flyash is maximized
in the SCC mixes as a filler material.
Keeping in view the idea explained above, a detailed
and a systematic experimental program is laid down
as explained in the next paragraphs. The main ob-
jective of the present investigation is:
Abstract
The use of self-compacting concrete (scc) in general building and civil engineering constructions is becoming popular
over the years ever since it was invented and guide-lines have been formulated by the efnarc (european federation of
national association representing concrete) in 2005. Although in india, we do not have any specific codal provisions for
scc similar to normal concrete, considerable research has been done in both development of scc and its applications with
various admixtures and fibers to enhance the properties of scc in hardened state. As scc is very sensitive to variations
in moisture content and gradation of aggregates, construction sites face difficulties in free flow of scc.
In order to overcome this, viscosity modifying admixtures (vmas) have been introduced by the researchers apart from
efnarc releasing guide-lines for vma for concrete in september-2006, as extensive studies have become imperative on
the role of vma in scc.
The primary aim of this study is to explore the influence of vma on fresh and hardened properties of scc with varying
dosage of mineral admixture namely fly ash and chemical admixture i.E. Super plasticizer for standard grade scc mixes
of m30 grade. It is proposed to design m30 grade scc concrete mix and study in detail the fresh and hardened proper-
ties like 3-day, 7-day and 28-day compressive strengths for the mixes with the above variables. The test results of the
specimens shall be compared for compressive strength of different mixes of scc and control mix and arrive at specific
conclusions on the role of vma in the presence of admixtures.
1401-1402

2. 123
International Journal of Research and Innovation (IJRI)
To study the effect of the viscosity modifying ad-
mixtures on fresh and hardened properties of M30
grade self compacting concrete with different dos-
age of fly ash by using Nansu mix design and ra-
tional mix design procedure.
With the above objectives in mind the experimental
program is categorized as detailed below.
• Casting of cubes 3 for each type of mix say control
mix, 20% replacement of fly ash,30% replacement
of fly ash and with different dosage of VMA.
• In this study, M30grade of SCC with different fly
ash dosage and VMA dosage were designed based on
Nan Su method and rational method, to determine
the effect of VMA on SCC.The grade of concrete and
age of curing were the parameters in the study.
A detailed experimental program was planned to
achieve the objective of the study is explained in
Chapter – 4.
EXPERIMENTAL INVESTIGATIONS ON SELF
COMPACTING CONCRETE
GENERAL
In this chapter,wide spread applications of scc have
been restricted due to lack of standard mix design
procedure and testing methods. It is pertinent to
mention that only features of scc have been includ-
ed in indian standard code of practice for plain and
reinforced concrete (fourth revision), [2000]. Slump
flow test, l-box test, v-funnel test, u-box test, orimet
test & gtm screen test are recommended by efnarc
[european federation of producers and applicators
of specialist products for structures, may 2005] for
determining the properties of scc in fresh state.
MATERIALS
Cement
Coarse Aggregate
Fine Aggregate
Fly Ash
Super Plasticizer
Viscosity Modifying Admixture (VMA)
Water
PHASE I: DEVELOPMENT OF PLAIN SCC AND IN-
VESTIGATIONS ON ITS FRESH AND HARDENED
PROPERTIES
In this phase of investigations, M30 grade SCC mix
is developed using mineral and chemical admix-
tures to study its fresh and hardened properties.
For developing SCC of M30 grade, the mix propor-
tions were designed based on the method suggested
by Nan-Su et al (2001) and SV Rao et al(2010) us-
ing fly ash as mineral admixture and chemical ad-
mixtures like Super Plasticizers (SP) and Viscosity
Modifying Agents (VMA). Finally, SCC mixes which
have given required compressive strength with sat-
isfactory fresh properties were taken for the next
phase of investigations. This is explained in detail
as given below.
Mix Design and Trial Mix Proportions of Self
Compacting Concrete
An SCC mix of M30 standard grade was aimed and
the initial mix proportion was obtained using the
mix design methods as mentioned above. The mix
proportion thus obtained was fine-tuned by incor-
porating different guidelines available and making
various trial mixes to obtain the mix which satisfies
the required fresh and hardened properties. The de-
tailed mix design calculations are given in Appendix
I. The final mass of ingredients for 1m3 of SCC is as
follows:
Mass of Cement = 330.0 kg
Mass of filler (Fly Ash) = 150.0 kg
Mass of water = 186.0 kg
Mass of Coarse Aggregate (CA) = 795.5 kg
Mass of Fine Aggregate (FA) = 870.4 kg
Super plasticizer dosage = 1.8% by weight of cement
VMA dosage = 0.1 to 0.6% by weight of cement (bwc)
2Mixing of Ingredients
The mixing of ingredients was carried out in a power
operated pan type concrete mixer. Initially coarse
aggregate, fine aggregate, cement and fly ash were
put in the pan mixer and mixed in the dry state
for a few seconds. Then Super plasticizer (SP) was
added to the water, thoroughly mixed and added
to the material in the concrete mixer. The required
amount of VMA was added and further mixed till a
mix of required uniform consistency was achieved.
Methods of Evaluation of Workability of SCC
Workability test methods available for conventional
concrete mixes are not adequate for evaluation of
workability of Self-Compacting Concrete mixes as
they are not sensitive to ascertain all the require-
ments of Self-Compacting Concrete mixes. Different
test methodologies were developed to characterize
the fresh properties of
SCC mixes. No single method was available till date,
to assess relevant workability requirements. Hence,

3. 124
International Journal of Research and Innovation (IJRI)
the SCC mixes have to be tested using more than
one test for measuring different workability parame-
ters. The following are the test methods available to
characterize the desired workability requirements
and for the finalization of fresh Self-Compacting
Concrete mixes.
Slump Flow Test and T 50 cm Test
The slump flow test is used to ascertain the free flow
of Self Compacting Concrete without obstructions.
Slump Flow Test
Procedure:
• About six litres of SCC is required to perform this
test.
• First moisten the base plate and the inside sur-
face of slump cone. Place base plate on level stable
ground and the slump cone centrally on the base
plate and hold down firmly.
• Fill the slump cone with SCC using a scoop. Do
not tamp the concrete. Strike off the concrete sur-
face with the top level of the cone with a trowel.
• Any surplus concrete in and around the base of
the slump cone has to be removed.
• Lift the cone vertically and allow the SCC to flow
freely.
• Start the stopwatch simultaneously, and record
the time taken for concrete to spread upto the
500mm circle marked. (This is called T50 cm test).
• Afterwards, measure the final diameter of the con-
crete spread in two or more perpendicular direc-
tions.
• Then calculate the average of the measured diam-
eters which is termed as the slump flow.
Interpretation of the results:
Higher slump flow value indicates greater ability to
fill the formwork under its own weight. A minimum
value of 650mm is recommended for SCC. The T50
time is also an indication of SCC flow. A lower time
means greater flowability. The research suggested a
time range of 3-7 seconds for general civil engineer-
ing applications and 2-5 seconds for general hous-
ing applications (T.Suresh Babu,2008).
V-Funnel Test
This test is performed to determine the filling ability
(flowability) of the Self-Compacting Concrete.
Procedure for V-Funnel Test :
• Take about 12 litres of concrete to perform this
test.
• Keep the V-funnel on level ground.
• Moist the inside surface of the V-funnel
• Open the trap door to drain out any surplus water.
• Now close the trap door and keep a bucket under-
neath the V-funnel.
• Now fill the V-funnel apparatus completely with
the SCC without any compaction or tamping. Then
strike off the excess concrete and level the top with
the help of a trowel.
• Open the trap door within 10 seconds after filling
the funnel.
• Now allow the concrete to flow out of the funnel
under gravity.
• Start a stopwatch immediately after the trap door
of the funnel is opened. Record the flow time taken

4. 125
International Journal of Research and Innovation (IJRI)
for the concrete to discharge completely from the
funnel. This is recorded when light is seen from the
top through the funnel.
• The test is to be completed within 5 minutes time.
Procedure for flow time at T5 minutes
• Take the same setup as above of v-funnel test and
do not clean the inside of the funnel again.
• Close the trap door and fill the v-funnel apparatus
completely with concrete, again without compac-
tion. Strike off the excess concrete on top and level
the top surface with a trowel.
• Place a tub underneath the funnel.
• Open the funnel door after 5 minutes after the
filling of the funnel the second time and allow the
concrete to flow freely under gravity.
• Start the stopwatch simultaneously when the door
is opened, and record the time taken for the con-
crete to completely come out. This is the flow time
at t5 minutes. This time is to be recorded when the
light is seen from the top of the funnel.
Interpretation of results:
The above test measures the ease of flow of the scc;
shorter flow times indicate greater flow ability. For
scc, 10 seconds flow time is considered appropriate.
Five minutes after settling, segregation of concrete
indicates a lesser flow with an increase in the flow
time.
L Box Test
The test is for assessing the flow of the SCC and the
blocking resistance.
Procedure:
• Take about 14 litres of self-compacting concrete
for performing this test.
• Place the apparatus on a level ground and ensure
free opening and closing of sliding shutter. Moisten
the inside surface of the
L box apparatus.
• Fill the vertical section of the apparatus with the
scc sample.
• Lift the sliding gate and allow the scc to flow out
into the horizontal section.
• Start the stopwatch simultaneously, and the time
taken for the scc to reach the 200mm and 400mm
marks are to be recorded.
• The heights “h1” and “h2” are measured, when the
scc stops flowing. Calculate the ratio h2/h1, which
is the blocking ratio.
• The complete test is to be performed within a time
of 5 minutes.
Interpretation of results:
If the concrete flows freely without any resistance,
H2/H1 will be unity. Therefore the nearer the ‘block-
ing ratio’ to unity, the better the flow of the SCC.
The European Guidelines [84] suggests a minimum
value of 0.8.
Acceptance criteria for SCC
S.No Method Unit Minimum Maximum
1 Slump flow by
Abrams cone
mm 650 800
2 T 50 Slump flow sec 2 5
3 J-ring mm 0 10
4 V-Funnel sec 6 12
5 V-Funnel @ T
5min
sec 0 +3
6 L-box (h2/h1) 0.8 1
7 U-box (h2/h1)
mm
0 30
8 Fill box % 90 100
9 GTM Screen
stability test
% 0 15
10 Orimet sec 0 5

5. 126
International Journal of Research and Innovation (IJRI)
Testing of scc in fresh state
The scc mix in fresh state was tested to get fresh
properties like filling ability, passing ability and
segregation resistance by performing slump cone,
v-funnel, and l-box tests as explained above.
Casting of specimens
After satisfying the requirements of scc in fresh
state, the mix was placed in moulds and allowed to
flow and settle by itself. Any excess scc on the top of
the moulds was removed with a trowel.
Curing of scc specimens
The scc specimens were kept undisturbed at room
temperature for 24 hours after casting. Then the
specimens were removed from the moulds and
transferred to curing ponds containing fresh pota-
ble water as shown below.
Testing of hardened scc
A proper time schedule for testing of hardened
scc specimens was maintained in order to ensure
proper testing on the due date. The specimens were
tested using standard testing procedures as per is :
516 – 1959.
Compression test
After the required curing period, the scc cubes were
taken out of the curing tanks and the moisture was
wiped off to make the surface dry. They were placed
in the compression testing machine (ctm) in such
a way that the face perpendicular to the direction
of pouring of scc mix was on the bearing surfaces
and the load was applied centrally at a uniform rate
of 140 kg./Sq.Cm./Minute until the failure of the
specimens, in accordance with is 516–1959. The
testing was done on a 3000 kn capacity compres-
sion testing machine.
RESULTS OF EXPERIMENTAL INVESTIGATIONS
ON FRSCC
This chapter deals in detail with the results of ex-
perimental investigations carried out in different
phases.
PROPERTIES OF MATERIALS
The properties of materials used for developing SCC
are shown in tables.
S.No Properties Test results Requirements as
per IS:12269-1987
1 Normal consist-
ency
32%
2 Specific gravity 3.10
3 Initial setting time 50 min Not less than 30
min
4 Final setting time 166 min Not more than 600
min
5
Compressive
strength
40 N/mm²
Should not be less
than 37 N/mm²
7 days
28 days
58 N/mm²
Should not be less
than 53 N/mm²
Properties of Aggregate
Sieve analysis of Fine Aggregate
S.No IS Seive
size
Weight
retained
in gm
Cumula-
tive weight
retained in
gm
Cumula-
tive %
weight
retained
Cumula-
tive %
passing
Grading
limits IS
383-1970
zone II(%)
1 10 mm 0 0 0 100 100
2 4.75 mm 9 9 0.9 99.1 90-100
3 2.36 mm 25 34 3.4 96.6 75-100
4 1.18 mm 163 167 19.7 80.3 55-90
5 600
microns
408 605 60.5 39.5 35-59
6 300
microns
210 815 81.5 18.5 8-30
7 150
microns
165 980 98.0 2.0 0-10
8 <150
microns
20 -- -- -- --
9 total 1000 264
Fineness Modulus = Cumulative Percentage weight
retained / 100
= 264/100= 2.64
Fine aggregate belongs to Zone II
Sieve analysis of Coarse Aggregate
s.no IS Seive
size
Weight
re-
tained
in gm
Cumula-
tive weight
retained in
gm
Cumula-
tive %
weight
retained
Cumula-
tive %
passing
Grading
limits
12.5 mm
graded ag-
gregate IS
383-1970
zone II(%)
1 20 mm 0 0 0 100 100
2 12.5
mm
400 400 8 92 90-100
3 10 mm 2200 2600 52 48 40-85
4 4.75
mm
2100 4700 94 06 0-10
5 2.36
mm
300 5000 100 -- --
6 Total 5000
Coarse aggregate belongs to 12.5 mm Graded ag-
gregate

6. 127
International Journal of Research and Innovation (IJRI)
Properties of fine and coarse aggregate
S.No Property Fine
aggregate
Coarse
aggregate
1 Specific grav-
ity
2.6 2.6
2 Loose density 1650 kg/m3 1440 kg/m3
3 Rodded den-
sity
1775 kg/m3 1695 kg/m3
Properties of fly ash
S.No Characteristics of fly ash properties
1 Specific gravity 2.05
2 Surface area 410 m²/kg
Chemical Composition of Fly ash
(Source: Civil Aid Techno clinic Private Limited)
S.NO Characteristics Test
conducted
Required
Percentage as
per IS:3812-
2003 (reaf-
firmed 2007)
1 Silicon
dioxide(Sio2)+aluminum
oxide(Al2o3)+iron
oxide(Fe2o3),percent
(minimum)
94.74 70%
2 Silicon
dioxide(Sio2),percent
(minimum)
63.38 35%
3 Magnesium oxide(MgO),
percent(maximum)
1.08 5.0%
4 Total sul-
phur as sulphur
trioxide(So3),percent
(maximum)
0.11 3.0%
5 Loss of ignition, percent
(maximum)
0.10 5.0%
Properties of Super Plasticizer
(Source: BASF Chemical Company India Limited)-
Master Glenium Sky8233
S.NO Parameter Specifications(as per
IS:9103)
Results
1 Physical state Reddish brown liquid Reddish
brown
liquid
2 Chemical
name of ac-
tive ingredi-
ent
Poly carboxyl ate poly-
mer
Poly car-
boxyl ate
polymer
3 Relative den-
sity @250c
1.080(+/- 0.02) 1.081
4 pH Minimum6 6.88
5 Chloride con-
tent (%)
Maximum 0.2 0.0056
6 Dosage 0.5 to
1.5 litres
per 100
kg of ce-
ment
Properties of viscosity modifying admixture
(Source: BASF Chemical Company India Limited)-
GleniumStream 2
S.NO Parameter Results
1 Form or state Liquid
2 colour Colorless
3 Specific gravity 1.01+ 0.01 @25o
c
4 Chloride content Nil
5 pH 8+1
6 dosage 0.05 to 1.3% by weight of
cement
Fresh propertiesof self compacting concrete
mixes and control concrete
S.No SCC Mix
Fresh properties
Slump
flow(mm)
T50(sec) V-Fun-
nel
(sec)
1 Control mix + SP 695 3.28 4.15
2 Control
mix+SP+VMA0.1%
691 3.33 4.84
3 Control
mix+SP+VMA0.2%
684 3.39 5.26
4 Control
mix+SP+VMA0.3%
675 3.42 5.95
5 Control
mix+SP+VMA0.4%
663 4.27 6.82
6 Control
mix+SP+VMA0.5%
654 4.87 7.53
7 Control
mix+SP+VMA0.6%
649 5.01 9.86
8 20% FA+SP 665 3.35 6.69
9 20%
FA+SP+VMA0.1%
662 3.49 7.02
10 20%
FA+SP+VMA0.2%
660 3.74 7.45
11 20%
FA+SP+VMA0.3%
658 3.86 7.63
12 20%
FA+SP+VMA0.4%
640 4.96 8.55
13 20%
FA+SP+VMA0.5%
632 5.82 9.34
14 20%
FA+SP+VMA0.6%
627 6.60 10.36
15 30% FA+SP 657 4.76 7.13
16 30%
FA+SP+VMA0.1%
653 4.82 7.43
17 30%
FA+SP+VMA0.2%
650 5.05 8.25
18 30%
FA+SP+VMA0.3%
648 5.10 8.53
19 30%
FA+SP+VMA0.4%
595 6.88 10.88
20 30%
FA+SP+VMA0.5%
553 7.76 12.33
21 30%
FA+SP+VMA0.6%
498 8.01 14.42

7. 128
International Journal of Research and Innovation (IJRI)
Hardened properties of self compacting concrete
mixes and control concrete
S.No SCC Mix
Hardened properties
(compressive strength N/mm²)
3 days 7 days 28 days
1 Control mix + SP 37.17 43.28 45.21
2 Control
mix+SP+VMA0.1%
37.53 44.18 46.22
3 Control
mix+SP+VMA0.2%
38.46 46.10 48.38
4 Control
mix+SP+VMA0.3%
35.26 42.86 50.96
5 Control
mix+SP+VMA0.4%
35.08 40.33 46.30
6 Control
mix+SP+VMA0.5%
32.01 37.43 42.96
7 Control
mix+SP+VMA0.6%
30.36 33.89 39.42
8 20% FA+SP 33.19 36.34 40.73
9 20%
FA+SP+VMA0.1%
33.98 37.88 42.50
10 20%
FA+SP+VMA0.2%
35.62 39.46 43.62
11 20%
FA+SP+VMA0.3%
36.37 39.93 46.24
12 20%
FA+SP+VMA0.4%
30.13 34.17 39.75
13 20%
FA+SP+VMA0.5%
29.56 32.80 38.22
14 20%
FA+SP+VMA0.6%
27.13 31.99 37.12
15 30% FA+SP 31.94 35.37 35.84
16 30%
FA+SP+VMA0.1%
32.17 35.85 36.87
17 30%
FA+SP+VMA0.2%
33.55 36.22 37.22
18 30%
FA+SP+VMA0.3%
33.90 36.98 38.23
19 30%
FA+SP+VMA0.4%
27.11 33.75 37.32
20 30%
FA+SP+VMA0.5%
25.68 29.22 36.52
21 30%
FA+SP+VMA0.6%
23.76 27.35 35.39
Graph showing Variation of 28 days Cube Com-
pressive Strength for Control Mix
Graph showing Variation of 28 days Cube Com-
pressive Strength for 20% Replacement of Fly
ash
Graph showing Variation of 28 days Cube Com-
pressive Strength for 30% Replacement of Fly
ash
CONCLUSIONSON TEST RESULTS OF SCC
1.Based on the present project work on influence of
viscosity modifying admixtures on fresh and hard-
ened properties of self compacting concrete with
varying dosage of fly ash,Concrete mixes-study of
compressive strength characteristics, the following
conclusions are drawn.
2.The use of appropriate dosage of super plasticizer
and viscosity modifying agent is essential to main-
tain the fresh properties of self-compacting con-
crete.
3.In this case, a VMA dosage of 0.3% is obtained as
an optimum dosage by suitablyadjusting the dosage
of admixtures.
FRESH PROPERTIES:
1.VMA has a substantial influence on fresh proper-
ties of SCC. A small change in VMA makes a sub-
stantial change in SCC properties i.e., flowing abilit
y,passingability,stability,segregation resistance.
2.In this investigation, as the VMA dosage was in-
creasing from 0 to 0.6% the flowing ability and pass-
ing ability of SCC decreased.

8. 129
International Journal of Research and Innovation (IJRI)
HARDENED PROPERTIES:
1.The target mean strength has been attained in al-
most all the mixes.
2.With the increase in VMA content the compressive
strength is varying i.e.,
the strength increased from 0.1 to 0.3% of VMA dos-
age and then decrease from 0.3 to 0.6%. hence the
dosage of 0.3% VMA gives maximum strength.
APPENDIX SCC MIX DESIGN
GENERAL GUIDE LINES FOR DESIGN OF SCC
MIXES
Scc mixes contain large quantity of powder (mate-
rial whose particle size is smaller than 0.125Mm) to
maintain plastic yield of the properties of fresh con-
crete. Further, it also requires super plasticizer to
ensure sufficient fluidity for sufficient time without
undergoing large slump loss. Viscosity modifying
agents and other admixtures are also added to en-
sure fully cohesive and stable mixes. To achieve flu-
idity, cohesiveness and homogeneity, three different
aspects were identified by okamura. They are :
• Reduction in coarse aggregate fraction in order to
reduce the frequency of collision of friction between
the particles to increase the fluidity of concrete.
• Increase in the paste content for further improve-
ment in fluidity.
• Managing the viscosity of the scc to reduce the
risk of blocking of concrete when it flows through
congested reinforcement. The typical ranges of pro-
portions and quantities are given by efnarc(2005) in
order to obtain self-compactability which are given-
below. Further modifications of trial mixes are nec-
essary in the laboratory to meet strength and other
performance requirements of the actual mixes.
• Water/powder ratio (by volume) : 0.80 To 1.10 Of
total powder content
• Water :160 to 240 litres per cubic meter.
• Coarse aggregate content should be normally in
the range of 28 to 35 per cent by volume of the scc
mix.
• Generally, the mix has to be designed to ensure
that the concrete is capable of maintaining its re-
quired fresh properties inspite of variations in the
quality of raw materials. Viscosity-modifying ad-
mixtures are used for compensating the variations
due to any fluctuations in the grading of fa and the
moisture content in the aggregates.
VARIOUS METHODS OF MIX DESIGN
Even though there are no established scc mix de-
sign procedures by bis, certain methods were sug-
gested for arriving at these quantities by different
organizations and researchers. Various methods
available for obtaining the trial mixes are:
1. European practice and specifications
2. Mix design method proposed by gomes, ravindra-
gettu et al
3. Sedran et al method
4. Rational mix design proposed by svrao et.Al.
5. Nan-su et al method
6. Method proposed by jagadishvengala
7. The japanese method
MIX DESIGN AND TRIAL MIX PROPORTIONS OF
SELFCOMPACTING CONCRETE
SCC mix with a compressive strength of 30 MPa
with 85% control factor was aimed at. The initial
design mix proportion is obtained by using Nan-Su
et al(2001) method andrational mix design proposed
by SV Rao et. al(2010). This mix proportion was
fine-tuned by incorporating various guidelines and
laboratory trials to obtain SCC mix which satisfies
the fresh and hardened properties.
MIX DESIGN
1.Target strength
Target mean strength= fck+t*s
=30+1.65*5 =38.25Mpa
Calculation of Fine and Coarse Aggregate Con-
tents Fine and coarse aggregate quantities are
calculated considering unit volumes of loose satu-
rated surface dry fa and ca, packing factor (pf) and
volume ratio of fine and total aggregate.
Wca =pfx wcal (1-s/a)
Wfa = pf x wfal (s/a)
S/a = volume ratio of fine aggregate to total aggre-
gate. It is generally taken between 50% to 57%
Loose density ofca: 1455 kg/m3
Loose density of fa: 1635 kg/m3
Rodded density of ca: 1670 kg/m3
Rodded density of fa: 1710 kg/m3
The term “packing factor (pf) “is defined as the ratio
of mass of aggregate of tight packed state to that of
loose packed state(lower pf value is preferred )
Pf (for coarse aggregate): 1670/1455 = 1.147~1.15
Pf (for fine aggregate): 1710/1635 = 1.0458~1.05
W cal -unit volume mass of loose saturated surface
dry ca: 1455 (kg/m³)
W fal -unit volume mass of loose saturated surface
dry fa: 1635 (kg/m³)
WCA = Content of CA in SCC, kg/m3
WCA =PFX Wcal (1-S/a)
54
= 1.15 X 1455 (1-0.54) = 769.695g/m3
WFA = Content of FA in SCC, kg/m3
WFA = PF X Wfal X (S/a)
= 1.05 X 1635 x 0.54 = 927.045kg/m3
Calculation of Cement Content (C)
(As per the curves given in the rational mix design
procedure by SV Rao et al(2010)
C = 10.24 + 9.535 x strength of concrete
i.e, C = 10.24 +9.535 x 38.25 = 374.95 kg/m3

9. 130
International Journal of Research and Innovation (IJRI)
Calculation of Mixing Water Content Required
by Cement
W wc = (w/c) C
W wc = Mixing water required by cement, kg/m3
W/c = 0.55
= 0.55 X 374.95 = 206.2 liters
Calculation of Filler
(AS per the curves given in the rational mix design
procedure)
% Fly ash = 68.43 – 0.535 x grade of concrete
= 68.43 – 0.535 X 38.25 = 47.96
Fly ash = 374.95 X 47.96 / 64.51 = 278.79 Kg
Calculation of Super plasticizer Dosage
The dosage of super plasticizer can be obtained by
experience or carrying marsh cone test on mortar.
Super plasticizer dosage determined in the present
case is 1.8% by weight of cement.
Trial Mixes and Adjustment of Mix Proportion
Trial mixes were carried out using the designed con-
tents of different materials. Different trial mixes are
tried in the laboratory to obtain an SCC mix, which
satisfies the required fresh and hardened proper-
ties.
Finally small changes are made to the proportions
of ingredients obtained by Nan Su et al method of
mix design and based on the trail mixes, the final
proportions of SCC mix are obtained for different
filler materials and their combinations.
Final mass of ingredients used in the present in-
vestigations per 1 m3
of SCC are as follows:
Mass of Cement = 330 kg
Mass of filler (Fly Ash) = 150 kg
Mass of water = 186 kg
Mass of CA = 795.5 kg
Mass of FA = 870.4 kg
Super plasticizer dosage = 1.8% by weight of cement
VMA dosage = 0.1 to 0.6% by weight of cement
REFERENCES
1.Hajime Okamura and Masahiro Ouchi ; Invited Paper on “Self
Compacting Concrete”-Journal of Advanced Concrete Technol-
ogy Vol.1, No.1, pp5-15, April 2003 Japan Concrete Institute. 32.
2.Nan Su, Kung-Chung Hsu, His-Wen Chai “A Simple Mix Design
Method for Self-Compacting Concrete” Journal of Cement and
Concrete Research 31(2001) pp 1799-1807.
3.Okamura H., et. al. “Mix-Design for Self-Compacting Concrete”,
Concrete Library of JSCE, No.25, June 1995(ND), pp107-120.
4.Ouchi M. and Okamura H. “Effect of Superplasticizer on Self-
Compactability of Fresh Concrete”, Journal of the Transportation
Research Board, 1997, pp37-40.
5.Borsoi. A, Collepardi. M, Collepardi. S, Croce. E.N., Passuelo .A
“Influence of Viscosity Modifying Admixture on the Composition
of SCC”Supplementary volume of Eighth CANMET/ACI Interna-
tional Conference on Superplasticizers and other Chemical Ad-
mixtures in Concrete, October 29-November 1, 2006, Sorrento,
Italy pp253-261.
6.Collepardi. M “Mechanical Properties of Self-Compacting and
Flowing Concretes”, Terence C. Holland Symposium on Ad-
vances in Concrete Technology – 2007, George C. Hoff, Editor.
pp379384.
7.Frances Yang “Self – Consolidating Concrete”, CE 241: Con-
crete Technology, Spring 2004 ; Report # 1, March 9, 2004. 23.
8.Lachemi M and Hossain K. M. A. “Self-Consolidating Concrete
incorporating New Viscosity Modifying Admixtures” Cement &
Concrete Research 34(2004), pp185-193.
9.The European Guidelines for Self–Compacting Concrete”
(Specification, Production and Use) May 2005.
AUTHOR
Shraddha,
Research Scholar,
Department Of Civil Engineering,
Aurora Scientific Technological and Research Academy,
Hyderabad India.
M.V.Seshagiri rao,
Professor,
Department Of Civil Engineering,
JNTU Hyderabad,
Hyderabad, India
K. Mythili
Associate professor ,
Department Of Civil Engineering,
Aurora Scientific Technological and Research Academy,
Hyderabad India.