IRJET- CRETEX – An Advanced and Futuristic Concrete
Main projor
1. STUDY ON WORKABILITY AND STRENGTH
CHARACTERISTICS OF FLY ASH CONCRETE, AND
TO INVESTIGATE THE SCM NATURE OF FLY ASH
Sheik Mohamed Subhan .H, M.K.Krivesh, S. Logeshwaran, V. Vignesh Kumar.
Mr. S. Arvindan
(Department of Civil Engineering, Bharath University, Selaiyur, Chennai, Tamilnadu, India.)
ABSTRACT
In the last decade, the use of supplementary cementing materials has become an integral
part of high strength and high performance concrete mix design. These can be natural
materials, by-products or industrial wastes, or the ones requiring less energy and time to
produce.
One of the most commonly used supplementary cementing materials is fly ash. Fly ash is a
by-product material obtained from the combustion of coal. It is used as pozzolanic material
in concrete, and has demonstrated significant influence in improving the properties like
water requirement, workability, setting time, compressive strength, durability of mortar
and concrete .
In this project we have given the dosage of fly ash from 0 % , 10 % , 20 % & 30%
Admixture (Plastiment BV 40) dosage is given from 0%, .5% & 1%.
CHAPTER 1
INTRODUCTION
1.1 GENERAL
Concrete, in some form or the other, has been in use for more than 6000 years. Babylonians and
Assyrians first used a mixture of clay, lime and water. Later civilizations developed these initial
mixes.
High performance concrete (HPC) has recently become very attractive to civil engineers and
material scientists . As it exhibits higher workability, greater mechanical properties and better
durability, Fly ash is used as cement replacement because fly ash is considered as valuable source.
Fly ash is residue left from burning coal, which is collected on an electrostatic precipitator. Most
fly ash is pozzolanic material, which means it’s a siliceous or siliceous-and-aluminous material
that reacts with calcium hydroxide to form a cement.
Fly ash was used 2000 years ago , when the Romans built the Colosseum in the year 100 A.D. -
that still stands the test of time!!
2. The ash generated from Volcanoes was used extensively in the construction of Roman structures.
Colosseum is a classic example of durability achieved by using volcanic ash.
This is a building constructed 2000 years ago and still standing today!
1.2 THE CHEMICALS OF FLY ASH
Because fly ash is a by-product material chemical constituents can vary considerably but all
fly includes:
◦ Silicon Dioxide (SiO2)
◦ Calcium Oxide (CaO)
◦ Iron (III) Oxide (FeO2)
Aluminum Oxide (Al2O3)
Fly ash contains a high percentage of silica in the form of silicon dioxide, which appears as
hollow glass spheres when viewed under a microscope. It is the silica in fly ash that reacts with
calcium hydroxide found in the cement paste of hardened concrete. Calcium hydroxide, a by-
product of the portland cement hydration process, is a very weak material that adds no structural
strength to concrete. When the silica in fly ash reacts with calcium hydroxide, however, good
things happen. Beneficial calcium silica hydrate (C-S-H) is formed. It is C-S-H that cements sand
and large aggregates into a solid mass known to us as concrete
1.3 PROPERTIES OF SUPERPLASTICIZERS (Plastiment BV 40)
Specific Gravity Type Colour
1.16 Modified Ligno sulphonate Dark brown
Dosage – 0.2% by weight of cement (normal)
Compliances:
-Conforms to ASTM C 494/C, Type A and confirms to both IS : 2645 and IS : 9103-99.
3. CHAPTER 2
LITERATURE REVIEW
2. LITERATURE REVIEW
Contribution of Fly ash to the properties of Mortar and Concrete International
Journal of Earth Sciences and Engineering ISSN 0974-5904, Volume 04, No 06 SPL,
October 2011, pp 1017-1023 conclude that, Fly ash blended concrete can improve the
workability of concrete compared to OPC. It can also increase the initial and final setting
time of cement pastes thereby improving the resistance of concrete to sulfate attack
expansion with showing higher compressive strength of concrete.
Advantages Of Using Fly Ash As Supplementary Material Jagadesh . Sunku
November 15-18, 2006 São Paulo – Brazil concludes that, Utilization of fly ash as SCM
prevents pollution, conserves natural resources and protects the environment.
Researches Toward a General Flexural Theory for structural concrete, By Hubert Rusch
The Journal of English American institute 1960 state that, Plastiment provides low slump
workability and stability on placement on the steeply slope surface.
Saeed Ahmad*25 - 26 August 2004 state that, values of water cement ratios could be
varied to study their effects on various properties of Concrete such as workability,
compressive strength.
4. CHAPTER 3
METHODOLOGY
3.1 FLOW CHART
The methodology followed is shown in flow chart fig 3.1
Fig 3.1 Flow chart of Methodology
5. 3.2 DESCRIPTION OF METHODOLOGY
3.2.1 Grade Of Concrete
In our project the concrete mix is M20 & M25 grade of concrete. The material used to
produce M20 & M25 grade of concrete are cement of 43 grade (OPC), coarse aggregate of size
20mm, fine aggregate (sand), fly ash , superplasticizer i.e, Plastiment BV 40,.
3.2.2 Preliminary Tests
The preliminary tests carried out are
3.2.2.1 Cement:-specific gravity, fineness, initial setting time, final setting time and
consistency test.
3.2.2.2 Fine aggregate:-sieve analysis, moisture contain, specific gravity
3.2.2.3 Coarse aggregate:-crushing strength, moisture contain, specific gravity.
3.2.3 Mix Design
After all the preliminary test, mix design is carried out, with reference to IS code 10262
3.2.4 Tests On Concrete
The following tests are carried.
3.2.4.1 Tests on fresh concrete
Slump test
Compaction factor test
3.2.4.2 Tests on hardened concrete
Compressive test
3.2.5 Analysis
After all the tests for fresh as well as harden concrete over the results which we got are
compared between the fly ash concrete of different dosage with convention concrete.
6. 3.3 TEST PROCEDURE FOR FRESH CONCRETE
Following are the procedures to perform the tests on fresh concrete.
3.3.1 Procedure For Compaction Factor Test
Weight the empty cylinder accurately and note it. Weight and fix it to the base of the
compaction factor apparatus. Weight the following material to prepare concrete for testing. 2.5kg
of cement, 4kg of sand and 8.25kg of coarse aggregate. Add water at the rate of 52% by weight of
cement to it and mix them thoroughly on a platform. Place the sample of concrete to be tested in
the upper hopper, up to the brim. After the concertinas come to rest open the trap door of the
lower hopper and allow the concrete to fall into the cylinder. This brings concrete into stranded
compaction. Trim off the excess concrete remaining above the top level of the cylinder. Wipe off
the outside of the cylinder. Weight the cylinder full of concrete. Take this weight as the weight of
partially compacted concrete. Empty the cylinder, after that, and again fill the cylinder with
concrete in five layers. The layers being rammed heavily so as to obtain full compaction. Strike
off the compacted excess concrete above the top of the cylinder carefully and weight the cylinder
with concrete. Take this weight as fully compacted concrete.
Compacting factor = weight of partially compacted / weight of fully compacted concrete.
3.4 TESTS ON HARDENED CONCRETE
Following are the procedures to perform the tests on harden concrete.
3.4.1 Procedure For Compressive test
3.4.1.1 Preparation Of Cubes .
Fill in the concrete into the mould of known size and compact it. The concrete using
tamping rod or vibrating table. the top surface of the specimens should be capped with a cement
past of stiff consistency and should be levelled, the method adopted for this is as follows.
Leave the concrete in the cube mould for about 2 to 4 hours. Scrap the top surface of the
concrete little and apply on it the cement paste of stiff consistency (also prepared 2 to 4 hours
earlier). and leave it there after 24 hrs or till the time specimen is taken out of the mould.
3.4.1.2 Curing
Submerge the specimen (after taking out from the mould) in clean, fresh water and leave
there till just prior to test i.e, 28 days.
7. 3.4.1.3 Testing
Remove the specimen from the water and wipe it clean. Note down the dimensions of the
specimen to the nearest 0.2mm and weight it accurately. Cleaning the bearing surfaces of the
testing machine and place the specimen in such a manner that the load shall be applied to opposite
sides of cube as cast and not to the top and bottom. After aligning the axis of the specimen
carefully apply the load slowly at approx. 140 kg/sq.cm/min. till the cube breaks. Record the
maximum load failure.
CHAPTER 4
MIX DESIGN
4.1 BASIC CONSIDERATIONS
Design of concrete mixes involves determination of the proportions of the given
constituents namely cement, water, coarse and fine aggregates and admixtures .If any, which
would produce concrete possessing specified properties both in the fresh and hardened states with
the maximum overall economy. Workability is specified as the important property of concrete in
the fresh state an compressive strength and durability are important properties of hardened
concrete. Hence the mix design is generally carried out for a particular compressive strength of
concrete with adequate workability so that the fresh concrete can be properly placed and
compacted to achieve the required durability .In special situations concrete can be designed for
flexural strength for any other specific property of concrete.
4.2 FACTORS IN THE CHOICE OF MIX DESIGN
Grade designation
Type of cement
Maximum nominal size of aggregate
Minimum water cement ratio
Workability
4.3 METHODS OF CONCRETE MIX DESIGN
The mix design methods being used in different countries are mostly based on empirical
relationships, charts and graphs developed from extensive experimental investigations. The
following are the different methods of concrete mix design
i. DOE Method
ii. ACI Method
iii. RRL Method
iv. IS Method
8. 4.3.1 DOE Method
The DOE method overcomes some limitations of IS method. In DOE method, the fine
aggregate content is a function of 600micron passing fraction of sand and not the zone of sand.
The 600-micron passing fraction emerges as the most critical parameter governing the cohesion
and workability of concrete mix thus sand content in DOE method is more sensitive to changes in
fitness of sand when compared to the IS method. The sand content is also adjusted as per
workability of mix. It is well accepted that higher the workability the greater is the fine aggregate
required to maintain cohesion in the mix. The water content per m3
is recommended based on
workability requirement given in terms of SLUMP and VEE-BEE time. It recommends different
water contents for crushed aggregates and for natural aggregates. The quantities of fine and coarse
aggregate are calculated based on plastic density. However the DOE method allows simple
correction in aggregate quantity for actual plastic density obtained at laboratory.
4.3.2 ACI Method
This method is based on determining the coarse aggregate based on, dry rodded coarse
aggregate bulk density and fitness modulus of sand. Thus this method takes into account the
actual voids in compacted coarse aggregate that are to be filled by concrete. This method is most
suitable for design of air – entrained concrete. This method gives separate values of water and
sand content for maximum size of aggregate up to separate values for 12.5 and 25mm down
coarse aggregate.
4.3.3 RRL Method
In this method, the aggregate to cement ratio are worked out on the basis of type of
aggregate, maximum size of aggregate and different level of workability. The relative proportion
of aggregates is worked on basis of combined grading curves. This method facilitates use of
different type of fine aggregate and coarse aggregate in the same mix. The relative proportion of
these can be easily calculated from combined grading curves. The values of aggregate to cement
ratio are available for angular rounded or irregular coarse aggregate.
4.3.4 Indian Standard Method (IS Method)
Indian standard method is used in this investigation and the corresponding principles and
procedure are given in the following subtitles .The IS method treats normal mixes (up to M35)
and high strength mixes (M40 and above) differently. This is logically because richer mixes need
lower sand content when compared with leaner mixes. The method also gives correction factor for
different water- cement ratio, workability and for rounded coarse aggregate. Is IS method, the
quantities of fine and coarse aggregate are calculated with the help of yield equations, which is
based on specific gravities of ingredients.
9. 4.4 DATA FOR MIX DESIGN
The following basic data are required to be specified for design of a concrete mix:
a. Characteristic compressive strength (that is, below which only a specified proportion
of test results are allowed to fall) of concrete at 28 days (fck).
b. Degree of workability desired.
c. Limitation on the water – cement ratio and the minimum cement content to ensure
adequate durability.
d. Type and maximum size of aggregate to be used.
e. Standard deviation (s) of compressive strength of concrete.
Table 4.1 Suggested Value Of Standard Deviation
Grade of Concrete
Standard deviation for different degree of control in N/mm2
Very Good Good Fair
M10 2.0 2.3 3.3
M15 2.5 3.5 4.5
M20 3.6 4.6 5.6
M25 4.3 5.3 6.3
M30 5.0 6.0 7.0
M35 5.3 6.3 7.3
M40 5.6 6.6 7.6
M45 6.0 7.0 8.0
M50 6.4 7.4 8.4
M55 6.7 7.7 8.7
M60 6.8 7.8 8.8
4.4.1 Degree of Quality Control Expected Under Different Site Condition
VERY GOOD – Fresh cement from single source and regular tests, weigh batching of all
materials, aggregate supplied in single size, control of aggregate grading and moisture content,
control of water added, frequently supervision, regular workability and strength test, and field
laboratory facilities.
GOOD – Carefully stored cement and periodic tests, weigh batching of all materials, controlled
water, graded aggregate supplied, occasional grading and moisture tests, periodic check of
workability and strength, intermittent supervision and experienced workers.
10. FAIR – Proper storage of cement, volume batching of all aggregate allowing for bulking of sand,
weigh-batching of cement, water content controlled by inspection of mix, and occasional
supervision and tests.
4.4.2 Target Strength for Mix Design
In order that not more than the specified proportion of test results are likely to fall below
the characteristic strength, concrete mix has to be designed for somewhat higher target average
compressive strength (fck). The margin over the characteristic strength depends upon the quality
control (expressed by the standard deviation) and the accepted proportion of results strength test
below the characteristic strength (fck), given by the relation:
Fck = fck + t × s
Fck = target average compressive strength at 28 days
fck = characteristic compressive strength at 28days
t = a static, depending upon the accepted proportion of low results and the number of tests; for
large number of tests, the value of ‘t’ is
Fck = fck + 1.65s
` Table 4.2 Value Of ‘t’
Accepted Proportion of
Low Result
‘t’
1 in 5 0.84
1 in 10 1.28
1 in 15 1.50
1 in 20 1.65
1 in 40 1.86
1 in 100 2.33
11. 4.4.3 Selection of Mix Proportions
4.4.3.1 Selection of Water Cement Ratio
Since different cements and aggregates of different maximum size, grading, surface
texture, shape and other characteristic may produce concretes of different compressive strength
for the same free water- cement ratio should preferably be established for the materials to be
used. In the absence of such data, the preliminary free water- cement ratio corresponding to the
target strength at 28 days may be selected from the relationship
Fig4.1 Generalised Relation between W/C and Compressive Strength of Concrete
Alternatively the preliminary free watre – cement ratio corresponding to the target average
strength may be selected from the relationship using the curve corresponding to 28 days cement
strength to be used for the purpose.
The free water-cement ratio selected should be checked against the limiting water-cement
ratio for the requirements of durability and lower of the two value adopted.
12. Fig 4.2 Relation between W/C Ratio and Concrete Strength for Different Cement Strength
4.5 ESTIMATION OF AIR CONTENT
Approximate amount of entrapped air to be expected in normal concrete is given
Table4.3 Approximate Air Content
Normal Maximum Size of Aggregate
in mm
Entrapped Air, Percentage Of
Volume Of Concrete
10 3.0
20 2.0
40 1.0
13. 4.6 SELECTION OF WATER CONTENT AND FINE TO TOTAL
AGGREGATE RATIO
For the desired workability, the quantity of mixing water per unit volume, of concrete and
the ratio of fine aggregate to total aggregate by absolute volume are to be estimated. Depending
upon the nominal maximum size and type of aggregate.
Table 4.4 Approximate Sand And Water Content Per Cubic Meter Of Concrete
For Grading Up To M35
Nominal Maximum Size of
Aggregate mm
Water Content Per Cubic
Meter Of Concrete
Kg
Sand As Percentage Of Total
Aggregate By Absolute
Volume
10 208 40
20 186 35
40 165 30
For other conditions of workability, water-cement ratio, grading of fine aggregate, and for
rounded aggregate, certain adjustments in the quantity of mixing water and fine to total aggregate
ratio are to be made.
4.7 CALCULATION OF CEMENT CONTENT
The cement content per unit volume of concrete may be calculated from the free water-
cement ratio and the quality of water per unit volume of concrete. The cement content is also
calculated shall be checked against the minimum cement content requirements of durability and
the greater of the two values adopted.
Table 4.5 Adjustment Of Values In Water Content And Sand Percentage For Other
Condition
Change In Conditions
Stipulated For Tables
Adjustment Required In
Water Content
% Sand In Total
Aggregate
For sand conforming to
grading Zone III or Zone IV
of Table 4, IS: 383-‘70
0
+1.5% for Zone I
-1.5% for Zone III
-3% for Zone IV
14. Increase or decrease in the
value of compacting factor by
0.1
±3% 0
Each 0.05 increase or
decrease in water-cement
ratio
0 ±1%
For rounded aggregate -15 kg -7%
4.8 CALCULATION OF AGGREGATE CONTENT
With the quantities of water and cement per unit volume of concrete and the ratio of fine
to total aggregate already determined, the total aggregate content per unit volume of concrete may
be calculated from the following equations:
……. (1)
.……. (2)
Where :
V = absolute volume of fresh concrete, which is equal to gross volume (m3
) minus the volume of
entrapped air
W = mass of water (kg) per m3
of concrete
C = mass of cement (kg) per m3
of concrete
Sc = specific gravity of cement
P = ratio of fine aggregate to total aggregate by absolute volume
Fa = total mass of fine aggregate and coarse aggregate (kg) per m3
of concrete
Sca = specific gravity of saturated surface dry fine aggregate and coarse aggregate respectively.
15. 4.9 MIX DESIGN FOR M20 GRADE OF CONCRETE
4.9.1 Design Stipulations
Choose w/c ratio against maximum w/c ratio for the requirement of durability.
(Table 5, IS:456-2000)
Grade of cement- M20
TARGET STRENGTH FOR MIX PROPORTIONING
f’ck = fck + 1.65 = 20 + (1.65 * 4) = 26.6 Nmm2
From table 5 of IS 456-2000, w/c ratio = 0.5
Selection Of Water Content
(From table 2 of IS 10262:2009)
Maximum water content = 186 kg
i.e 186 + (3/100) x 186=192 litres
Determination Of Cement Content
w/c ratio = 0.5
Actual Water required = 192 litres
= 192/0.5
= 384 kg/m3
(Table 5 of IS 456:2000)
Minimum cement content = 250 kg/m3
(384>250) hence correct ..
Determination Of Coarse Aggregates
Volume of coarse aggregate corresponding to 20 mm size aggregate and zone 3 of fine
aggregate
w/c ratio = 0.5 = 0.65
(table 3 of 10262:2009)
Volume of fine aggregate = 1-0.6 = 0.35
Mix Calculation
a) Volume of concrete = 1m3
b) Volume of cement = (mass of cement/Sp.gravity of cement)*(1/1000)
16. = (384/3.15)*(1/1000) = 0.1219 m3
c) Volume of water = (mass of water/Sp.gravity of water)*(1/1000)
= (192/1)*(1/1000) = 0.192 m3
d) Volume of admixture = 0
Volume of concrete including cement and water = [a-(b+c+d)]
= [1-(0.1219+0.192+0)] = 0.6861 m3
Mass of coarse aggregate = (vol.of all aggregates)*(Vol.of coarse
aggregates)*(Sp.gravity of coarse aggregates)*(1000)
= 0.6861*0.65*2.8*1000
= 1.24870*1000
= 1248.70 kg/m3
Mass of fine aggregate = [Vol.of all aggregates* Vol.of fine aggregate* Sp.gravity of
fine aggregate* 1000]
= 0.6861*0.35*2.61*1000
= 0.62675*1000
= 626.75 kg/m3
The final mix proportion of M20 grade of concrete per 1m3 become
Table 4.6 Mix Proportion for M20 grade concrete.
Water Cement Fine agg. Coarse agg.
192 384 626.75 1248.70
17. 4.9 MIX DESIGN FOR M25 GRADE OF CONCRETE
4.9.1 Design Stipulations
Choose w/c ratio against maximum w/c ratio for the requirement of durability.
(Table 5, IS:456-2000)
Grade of cement- M25
TARGET STRENGTH FOR MIX PROPORTIONING
f’ck = fck + 1.65 s
= 25 + (1.65 * 4)
= 31.6 Nmm2
From table 5 of IS 456-2000, w/c ratio = 0.40
Selection Of Water Content
(From table 2 of IS 10262:2009)
Maximum water content = 186 kg
i.e 186 + (3/100) x 186=192 litres.
Determination Of Cement Content
w/c ratio = 0.40
Actual Water required = 192 litre = 192/0.40 = 480 kg/m3
(Table 5 of IS 456:2000)
Minimum cement content = 280 kg/m3
(480>280)
Determination Of Coarse Aggregates
Volume of coarse aggregate corresponding to 20 mm size aggregate and zone 3 of fine
aggregate
w/c ratio = 0.4 = 0.66
(table 3 of 10262:2009)
Volume of fine aggregate = 1-0.66 = 0.34
Mix Calculation
a) Volume of concrete = 1m3
18. b) Volume of cement = (mass of cement/sp.gravity of cement)*(1/1000)
= (480/3.15)*(1/1000)
= 0.15238 m3
c)Volume of water = (mass of water/Sp.gravity of water)*(1/1000)
= (192/1)*(1/1000) = 0.192 m3
d) Volume of admixture = 0
Volume of concrete including cement and water = [a-(b+c+d)] = [1-(0.15238+0.192+0)]
= 0.65562 m3
Mass of coarse aggregate = (vol.of all aggregates)*(Vol.of coarse aggregates)* (Sp.gravity of coarse
aggregates)*(1000) = 0.65562*0.66*2.8*1000
= 1.21158*1000
= 1211.58 kg/m3
Mass of fine aggregate
= [Vol.of all aggregates* Vol.of fine aggregate* Sp.gravity of fine aggregate* 1000]
= 0.65562*0.34*2.61*1000
= 0.58179*1000
= 581.79 kg/m3
The final mix proportion of M25 grade of concrete per 1m3
become
Table 4.6.(a) Mix Proportion for M25 grade concrete.
Water Cement Fine agg. Coarse agg.
192 480 581.79 1211.58
19. CHAPTER 5
EXPERIMENTAL INVESTIGATIONS
5.1 PRELIMINARY TESTS
The following tests are conducted on cement, fine aggregate and coarse aggregate and the
results are tabulated in table 5.1, table 5.2 and table 5.3 respectively.
Table 5.1 Tests On Cement
Test Values
Specific Gravity 3.15
Fineness 91.00%
Consistency 31%
Initial Setting Time 30 min
Table 5.1 Tests On fly ash
Test Values
Specific Gravity 2.45
Fineness 97.00%
Table 5.2 Tests On Fine Aggregate
Test Values
Specific Gravity 2.61
Gradation Zone III
Table 5.3 Tests On Coarse Aggregate
Test Values
Specific Gravity 2.80
Aggregate Impact Value 26.94%
Aggregate Crushing Values 21.72%
Aggregate Abrasion Value
(Los Angeles)
22.1%
20. CHAPTER: 6
RESULTS AND DISCUSSION
The results obtained from the practical observation are discussed in this chapter.
6.1 RESULTS OF COMPACTION FACTOR TEST
In our mix design the assumed value of the compaction factor for M20 is 0.909 but when
we practically proceeded we got value of the compaction factor as 0.898 & for M25 is 0.925 but
when we practically proceeded we got value of the compaction factor as 0.810, it slightly varies
because of wear and tear while performing the experiment.
The values of compaction factor for the specimens with different percentage of fly ash &
admixture have been tabulated in table 6.1
Table 6.1 Values Of Compaction Factor
COMPACTION FACTOR
Admixture
(%)
Fly ash (%) Compaction Factor
0 0 0.909
0.5 0 0.9
1 0 0.898
0 10 0.888
0.5 10 0.885
1 10 0.88
0 20 0.873
0.5 20 0.869
1 20 0.856
0 30 0.853
0.5 30 0.849
1 30 0.83
GRADE : M20
Tabulation & Graphs :
It is observed that the compaction factor value increases with increase in
percentage of fly ash. Value of compaction factor of fly ash concrete varies from 0.909 to
0.830 (M20) .
The values of compaction factor is represented in figure 6.1. The graph is drawn between
dosage of fly ash , admixture and compaction factor.
22. COMPACTION FACTOR
Admixture (%) Fly ash (%) Compaction Factor
0 0 0.925
0.5 0 0.912
1 0 0.9
0 10 0.89
0.5 10 0.875
1 10 0.861
0 20 0.852
0.5 20 0.842
1 20 0.833
0 30 0.824
0.5 30 0.816
1 30 0.81
GRADE : M25
Tabulation & Graphs :
It is observed that the compaction factor value increases with increase in percentage of fly ash.
23. Value of compaction factor of fly ash concrete varies from 0.925 to 0.810 (M25)
0.74
0.76
0.78
0.8
0.82
0.84
0.86
0.88
0.9
0.92
0.94
0 0 0
COMPACTIONFACTOR
ADMIXTURE (%)
COMPACTION FACTOR
COMPARISON
FRESH CONCRETE
10% FLY ASH
CONCRETE
20% FLY ASH
CONCRETE
30% FLY ASH
CONCRETE
Fig 6.1.1 Compaction factor comparison graph for M25 grade concrete.
6.2 RESULTS OF SLUMP CONE TEST
In our mix design the assumed value of the slump cone for M20 is 2.45 but when we
practically proceeded we got value of the slump cone as 4 & for M25 is 1 but when we practically
proceeded we got value of the slump cone as 3.32, it slightly varies because of wear and tear
while performing the experiment.
The values of compaction factor for the specimens with different percentage of fly ash &
admixture have been tabulated in table 6.2
24. SLUMP CONE TEST
Admixture (%) Fly ash (%) Slump value (cm)
0 0 2
0.5 0 2.45
1 0 2.6
0 10 2.82
0.5 10 2.9
1 10 3.01
0 20 3.21
0.5 20 3.42
1 20 3.55
0 30 3.7
0.5 30 3.85
1 30 4
GRADE : M20
Tabulation & Graphs :
Table 6.2 Values Of Slump Cone test for Grade M20.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 0.5 1
SLUMPVALUE(cm)
ADMIXTURE (%)
SLUMP TEST COMPARISON
FRESH CONCRETE
10% FLY ASH CONCRETE
20% FLY ASH CONCRETE
30% FLY ASH CONCRETE
Fig 6.2 Slump cone test comparison graph for M20 grade concrete.
It is observed that the slump cone value increases with increase in percentage of fly ash.
Value of slump cone of fly ash concrete varies from 2.45 to 4 (M20)
25. SLUMP CONE TEST
Admixture (%) Fly ash (%) Slump value (cm)
0 0 1
0.5 0 1.25
1 0 1.5
0 10 1.95
0.5 10 2.13
1 10 2.36
0 20 2.5
0.5 20 2.65
1 20 2.74
0 30 2.89
0.5 30 3.01
1 30 3.32
GRADE : M25
Tabulation & Graphs :
It is observed that the slump cone value increases with increase in percentage of fly ash. Value
of slump cone of fly ash concrete varies from 1 to 3.32 (M25)
0
0.5
1
1.5
2
2.5
3
3.5
0 0 0
SLUMPVALUE(cm)
ADMIXTURE (%)
SLUMP TEST COMPARISON
FRESH CONCRETE
10% FLY ASH CONCRETE
20% FLY ASH CONCRETE
30% FLY ASH CONCRETE
Fig 6.2.1 Slump cone test comparison graph for M25 grade concrete.
26. 6.3 RESULTS OF COMPRESSIVE STRENGTH OF CONCRETE
The compressive strength of concrete is obtained after 28days curing by compressive
strength test.
Table 6.3 28days Compressive Strength Of Concrete
TESTS ON HARDENED CONCRETE
Admixture (%) Fly ash (%) Compressive
Strength (N/mm²)
0 0 26.01
0.5 0 26.12
1 0 26.33
0 10 27.01
0.5 10 27.39
1 10 27.98
0 20 28.46
0.5 20 28.94
1 20 29.09
0 30 31.04
0.5 30 31.36
1 30 31.63
GRADE : M20
Tabulation & Graphs :
It is observed that the compressive strength of the concrete is increased by increasing the
percentage of the fly ash within the recommended dosage i.e, 0 to 30 percentage of fly ash by
weight of the cement beyond this dosage it cause increase in strength. The 28 days compressive
strength is maximum at 30% of fly ash.
28. TESTS ON HARDENED CONCRETE
Admixture (%) Fly ash (%) Compressive
Strength (N/mm²)
0 0 28.46
0.5 0 28.94
1 0 28.99
0 10 29.85
0.5 10 30.09
1 10 30.4
0 20 31.06
0.5 20 31.33
1 20 31.69
0 30 32.86
0.5 30 33.4
1 30 33.99
GRADE : M25
Tabulation & Graphs :
25
26
27
28
29
30
31
32
33
34
35
0 0 0
COMPRESSIVESTRENGTH
(N/mm²)
ADMIXTURE (%)
COMPRESSIVE STRENGTH
COMPARISON
FRESH CONCRETE
10% FLY ASH
CONCRETE
20% FLY ASH
CONCRETE
30% FLY ASH
CONCRETE
Fig 6.3.1 Compressive strength comparison graph for M25 grade concrete.
It is observed that the compressive strength of the concrete is increased by increasing the
percentage of the fly ash within the recommended dosage i.e, 0 to 30 percentage of fly ash by
weight of the cement beyond this dosage it cause increase in strength. The 28 days compressive
strength is maximum at 30% of fly ash.
29. CHAPTER 7
CONCLUSIONS
The following conclusions are observed from the test results.
[1]. The workability of the concrete such as compaction factor increases with increase in
percentage of fly ash & admixture (from 0 %).
[2]. The workability of the concrete such as slump value increases with increase in percentage
of fly ash & admixture (from 0 %).
[3]. The compressive strength of the concrete increases from 0 % to 30 % of fly ash .
[4]. Both in case of Grade M20 & M25 the maximum strength was obtained at 30% of fly ash
at 28 days, and it is necessary to mention that as days goes on increasing, the cube gets
strengthens.
[5]. From this experimental investigation, we have been able to supplement the cement by fly
ash upto 12% . Thus, Supplementary cementing material (SCM) Nature was achieved at good
level in result.
32. REFERENCES
Abel J.D, Hover.KC, ‘Field study of the setting behavior of fresh concrete’ volume 22,
page 8.
Concrete Technology by M L GAMBHIR. Tata McGraw-Hill Company Limited New
Delhi.
Ferraris.CF, de Larrard.F ‘Modified slump test to measure rheological parameters’ of
fresh concrete’ volume 20, page 7.
IS: 10262-1982, recommended guidelines for concrete mix design, Indian Standard
Institution, 1982.
IS: 1199 – 1959 (Reaffirmed 1999) Methods of Sampling and Analysis of Concrete,
Bureau of Indian Standards, 1999.
IS: 2386 (Part I – IV) - 1963, “Methods of Test for Aggregates for Concrete”, Bureau of
Indian Standard, 1963.
IS: 383-1970, Coarse and fine aggregate from natural sources for concrete, Indian
Standards Institution, 1970.
IS: 516 – 1959 (Reaffirmed 1999) Edition 1.2 (1991-07) Methods of tests for strength of
Concrete, Bureau of Indian Standards, 2002.
IS 2430:1986 (METHODS FOR SAMPLING OF AGGREGATES FOR CONCRETE)
SP 23-1982(CONCRETE MIXES)
IS 10262-2009(CONCRETE MIX DESIGN)
IS 516-1959(METHODS OF TESTS FOR STRENGTH OF CONCRETE)
IS 383-1970(TESTS ON AGGREGATES)
Concrete technology by A.M.NEVILLE & J.J.BROOKS Addison Wesley Longman
Limited
